Session 3- Working with Java Operators and Expressions | Java & Selenium

all right so in the previous class uh we have seen 

how to work with variables and data types how can we Define the variables with the data types and 

different type of data types we have seen and in the today's session we will see operators so what 

is basically operator means operator uh basically a symbol which will perform certain operation or 

which will perform an operation okay for example uh let us say we'll have two different variable 

let's say in a = to 10 this is one variable in B = to 20 this is another variable a is one 

variable b is another variable both are having some data now if you want to add these two numbers 

what we will do now we can say A+ B so when I say A plus b this will add two numbers 10 + 20 now 

once added the result I will store in another variable here I will Define one more variable 

let's say int uh result like this now if I look at this particular simple code A and B are called 

variables A and B are called variables and here A plus b is called an expression okay a and plus b 

here we are calling as expression so what plus is doing here the plus is adding two numbers A and B 

right so which is basically called as an operator means an operator is a symbol which will perform 

an operation that's a simple definition operator is a symbol which will perform an operation 

there are multiple operators which we have so plus is a one of the operator so here plus 

is one operator which will perform addition of two numbers and what about this equal to equal 

to is also F operator equal to also one of the operator so what equal to we'll do here once 

a plus b is added the result will be stored into this variable so who is assigning the result 

into this variable equal to so equal to is called assignment operator okay so here plus also equal 

so these are all called operators and uh what is a and b initially before using this Expression A 

and B are just a variables now once you use those variables inside the expression we call them 

as operants a comma B called as operant so the variables which are participated inside this 

expression along with the operators they are called operant okay so operator means what it is a 

symbol which which will perform an operation which will perform an it can be any type of operation 

here plus is one one of the example plus will do the addition operation equal to will do the 

assignment operation so whatever value we have here 10 will assign to the a who is doing that 

equal to is doing it same thing 20 is assigning into the B so equal to is doing that which is 

also an operator and here plus is an operator which will perform addition of these two numbers 

and storing the result into variable is Again by equal to equal to stored the result in the result 

variable okay so operator means a symbol which will perform an operation the variables which 

are participate inside this expression we call them as a operants before using here just they 

are the variables but once you started using the variables inside this Expressions along with 

operators we call it as a operant okay now in Java there are various types of operators are 

provided so let me just list out here types of operators so to perform any type of operation we 

have to use different type of operators now what are the different type of operators provided by 

jav there are n number of operators mainly we will use these six types of operators very commonly so 

the first category arithmetic operators there are five operators comes under this Cate one is plus 

minus star slash and percent okay these are all called arithmetic operators and relational or 

comparison operators second category relational or comparison operators greater than greater 

than or equal to less than less than or equal to not equal to double equal to so these are 

all comes under relational or comparison and operators then logical operators end or not three 

operators which are comes under logical operators and plus plus is called increment operator minus 

minus is called decrement operator I will show you demonstration how can we use these all operators 

so Plus+ is increment operator minus minus is a decrement operator and equal to is an assignment 

operator we already discussed which will assign some data to the variable so like this we have 

some more assignment operators like plus equal to minus equal to Star equal to slash equal 

to percent equal to these are all assignment or we can also call as short hand operators and 

conditional or ternary operator question mark colum one operator question mark column is one 

single operator which is conditional or ternary operator so to toally these are the six type of 

operators which we are going to discuss so first thing let us start with arithmetic operators uh 

let's go to eclipse and uh go to our project so let's create a new package for today I can create 

by click on SRC new package I say day three click on finish so now we created a new package so 

inside this I'm going to create a new class whenever you start writing a new Java program you 

must create a class so how to create a class you can simply provide the name so here I'm giving 

some name operators demo and also I'm taking main method here select the checkbox and say 

finish now so which is created a new class and this is the main method so inside this block we 

have to write our Java code so inside this block we have to write a Java code now the first thing 

arithmetic operators so how to use this arithmetic operators so let us take two variables so mainly 

arithmetic operators works on numbers or numeric type of data so if we have integers or if 

you have a Flo or if you have a double so if you have a numeric data these operators will 

work so arithmetic operators basically we use to perform arithmetic calculations so what are 

the arithmetic calculations addition subtraction division multiplication modulo division so these 

are all basic arithmetic operations so to perform these operations we have to use the symbols and 

we need a numeric type of data okay so these operators Works only on the numeric type of data 

means all integers float double and so on so let me take take two integer variables here I can 

take int a = to 10 int Bal to or I can directly say b equal to 20 so because A and B are both are 

same data type I can just specify only once in a 10 B20 so two variables I have created now I will 

apply these operators on these two values so what I will do is I can directly write system out. PRN 

and simply I can say A+ B so when I say A plus b plus will perform the arithmetic operations when 

I say A plus b it will perform addition of two numbers 10 + 20 which is 30 now I want to write 

simple a meaningful message here I can say sum of A and B is so how to concatenate this this is 

a string whatever we put in the double quotation that will be printed as it is in the console 

window and a plus b is expression which will perform addition operation so how to concatenate 

these two we can put this a plus b in the bracket and then concatenate so here plus is acting as a 

two different things one is a concatenation other one is addition so when I use plus operator 

between two numbers it will perform addition operation when I use plus operator between 

two strings it will perform the concatenation operation or if I plus if I use operate between 

a string and number then also it will perform the concatenation operation and if I look at here 

this is a string and this will return the number after addition it will return return the number 

so between this I'm using plus operator means it will perform the concatenation so when I execute 

this this will print a meaningful message so sum of A and B is 30 so like this let us try to use 

other operators other arithmetic operations so here this is difference so substraction how can 

we do this so higher Valu is B right so I can say or else I can take a20 and B10 okay so here I can 

say a minus B A minus B so this is the expression a minus B is the expression this will perform 

subtraction and the result will be concatenated with the string so difference of a and t is a 

minus B and then multiplication so multiplication so multiplication of A and B is a star B Star 

is representing multiplication so whenever you want to multiply you can use star symbol 

and again plus is for just concatenation now division in division of A and B is a I can say 

A/B slash is a division operator and there is one more operator which we have modular division 

modular division means what percent a percent B is a modular division so here we need to understand 

what is the difference between Division and modular division slash and percentage so slash 

operator will return the coent value after uh division for example say 5 / 2 5 perc 2 so 

here I'm using two different operators so it will perform the division like 2 two's are four 

and one is a remainder right so when I use slash operator this will return the quent value which is 

two when I use percent operator this will return the remainder value so this is one okay so both 

are division operators but the slash will return return the coent value whereas percent will 

return the remainder value okay Division and modul and again we already know multiplication 

substraction and then addition so these are the basic arithmetic operators now let us try to 

execute run as Java application so now we can see the result here so this is we can get all 

the results so here I am not storing the result in any other variables I'm just directly uh doing 

the arithmetic operations and then I'm directly keeping inside the print statement suppose if you 

want to store the result in some variable okay then what you can do for example here I'm taking 

one more variable called inter result equal to A+ B and then you can use this variable directly 

here instead of printing a plus B you can directly print result so here you can just concatenation 

result so this is another way suppose if you want to store a result in some particular variable 

you take another variable so what you can do is you can store a plus b value in the result 

variable and what is the type of this variable again integer because a plus b will return the 

number which is integer so result also should be integer type and once you hold that result 

in a variable then you can print this variable so this is also another way and if you don't want 

to use any other variable then you can directly put this expression inside the printer instead 

of writing result you can just directly say A+ B so this is also fun you can put the result in 

another variable and print that variable or you can directly write an expression inside the 

print statement you will get the same output okay so this is all about arithmetic operators 

addition subtraction multiplication division and modular Division and now we have another type of 

operator relational or comparison operators and these operators especially we use to compare the 

values and most important especially when you're working with the conditional statement looping 

statements we frequently use these operators so relational and comparison operators so let us see 

how to use this relational or comparison operators next relational or comparison operators so greater 

than greater than or equal to less than less than or equal to this is not equal to and double equal 

so these are all comes under relational compassion operators now here all relational or comparison 

operat ators will return a Boolean value remember this always returns a Boolean value Boolean value 

means what yesterday we discussed what is Boolean value what is Boolean value Boolean means what yes 

either true or false it can be true or it can be false which is called as Boolean value so when 

I use relational operator or comparison operator that will return either true or false okay 

for example here I'm simply saying system. p a greater than b so greater than is what relational 

or comparison operator so what this greater than will do the greater than will compare a with B 

now what is the value of a here 20 what is the value of B 10 20 greater than 10 true or false 

20 greater than 10 true or false true right true so this expression will just print true that means 

the greater than symbol compare the two values and it can return either true or false okay suppose 

I'm writing the same statement like this a less than b less than a less than b a value is 20 B 

value is a 10 so 20 less than 10 is it true or false it is false because 20 less than 10 which 

is false so this expression will return return false okay let's try so all relational operators 

or comparison operators will return true or false basically they will return the Boolean values true 

or false okay and similarly we can also use other operators let's say system. out. and here I say a 

dater than or equal to B now tell me what is this expression will WR a greater than or equal to B 

so actually there are two comparisons here one is greater than one is equal to what does it mean 

so when this expression will returns true in two cases one is a should be greater than b in that 

case it will return true another case is what a should be equal to B if a and b values are equal 

then also it will returns true that's the reason greater than or equal to two comparisons a should 

be either greater than b or a should be equal to B so one of the condition should be satisfied 

so then only it will returns true now according to our values a is 20 b is 10 20 greater than or 

equal to 10 true or false true or false 20 greater than or equal to 10 true or false true why because 

greater than condition is true greater than is satisfied right 20 greater than b even though they 

are not equal still a is greater than b true right similarly here I will write like this a less 

than or equal to B true or false a less than b less than false right because a is 20 b is uh 10 

so 10 uh 20 less than 10 is false so whenever it become false then it will check another condition 

equal to a equal to b or not no a also not equal to B so obviously it will return return false 

this will return false so two conditions are two comparisons are inclusive here so you can 

say this is the true and this is a false so now what I will do is I will make B value also 20 so 

initially B value is what 10 now I'm making as a 20 should I Define the data Ty should I specify 

the data type here is it really need data type here should I Define data type not needed right 

why because B is already created with the integer type here we already specified b as an integer 

type so next time when you're referring the b or next time when you are changing the value of 

the B you no need to specify the data type again because this is a duplicated it will give you an 

error is clearly saying duplicate local variable B so you no need to specify the data type just 

reuse the variable and just change the value initial 10 now it becomes 20 now after changing 

this value I can simply say a greater than oral less than or equal to B and also I will write a 

greater than or equal to B now tell me what is an output of these two expressions a less than or 

equal to b a greater than or equal to B what is an output of these two statements obviously true why 

they are true why because it will first check the less than condition a less than b true or false 

false then it will check equality a equal B are true or false true so obviously it will return 

return true that means either less than or equal to one of them should satisfy now if you come to 

the second expression a greater than b a greater than b false a is not greater than b but a equal 

to B true so it is finally written true okay so two comparisons are here if first one is not 

matching then it will go to the second one if first one is not satisfying then compare with the 

second one okay so less than or equal to greater than or equal to now when I run this this two 

expressions will finally return true and true so all relational or comparison all relation 

or comparison operators are returning a Boolean values that you have to notice here true or false 

nothing else only true or false is written right now we say not equal to equal to so for example 

let's say syst P I can say a not equal to not equal to B what do this mean what is an output 

of this a not equal to B I'm I'm clear is saying a not equal to B true or false So currently A and 

B values are same but here what I'm expecting not equal to B so obviously what happens this will 

return false because a not equal to B false why because A and B are not equal it's equal actually 

a value 20 b value 20 both are equal but here I'm expecting not equal so it is obviously return 

false but if the same statement if you a same statement if you write like this a equal to b a 

equal to B now tell me what is a guys can you see my screen the font is visible to everyone can you 

please confirm otherwise I'll just try to increase some okay let me try to increase little bit 

okay it's too much larger okay now I think it is fine okay so now you can see a equal to B 

now a value is a 10 sorry a value is a 20 and B value is also 20 a value 20 b value is also 20 now 

what is an output of this expression a equal to B obviously it is true because the values are same 

I'm expecting double equal so when I run this this will give you false and true okay so if I notice 

here all relational or comparison operators will returns a Boolean value that means a true or 

false okay suppose I want to store the result in some variable I want to store some variable in 

a variable for example here I say a greater than b this is my expression and I want to store result 

in a variable let's say result because result variable we already defined as an integer here but 

here I'm taking Rees now tell me what is the type of this variable so a greater than b will return 

either true or false a boing value will be return returned now when I store that value in a variable 

what is the type of this variable obviously what type of variable it should be we storing a Boolean 

value into the variable remember this we are not storing number we are not storing integer but 

in the previous example A plus b will return the integer 20 plus 10 return the integer so this 

variable should be integer but here a greater than b will return the Boolean value so this variable 

should be what Boolean type of variable okay and after that you can just print result so like this 

you can directly put Expressions inside the print statements or else you can store the result in 

another variable and then you can print that variable so either way you can do it okay so this 

is rning false a greater than b is false because we already changed the value here okay so this is 

all about relational or comparison operators so what these operators will do these operators 

will compare two values it will compare two values and returns a Boolean value either true 

or false now similarly we also have something called uh logical operators the next category very 

important listen carefully because in the next topic conditional statements looping statement 

when I discussing those topics these operators are very useful so logical operators and or not 

so these three are called logical operators and logical operators also always returns a Boolean 

value returns Boolean value so Boolean value means again true or false so logical operators also 

so always returns a Boolean value true or false but what is the difference between relational 

and logical operators so relational operators we can use only between two variables if I look 

at here these operators will work between two variables A and B and these two variables can be 

any data type it can be numeric it can be string it can be character whatever it is so these 

relational operators we can use in all kinds of data types but logical operators we can use 

only Boolean data types we can use only Boolean data types that means we need a Boolean variables 

between these Boolean variables we can use logical operators so before discussing this end or not 

so let me just give you a simple table so that you can easily understand when these operators 

will return return true when these operators return false so as I said The Logical operators 

Works between two Boolean variables this is a fundamental Point Works between two Boolean 

values or variables anything okay so how it will work let me show you simple I'll take 

a small table in Excel sheet so let us try to understand how exactly The Logical operator 

works let me unra the okay so here I'm taking uh some variable called X and Y X and Y logical 

operator X and Y X r y not X not y okay and or not so this is both are same actually we just 

remember this and here I'm taking different combinations so and or not so these three 

operators Works between two buan variables so X and Y are the Boolean variables okay now 

here I'm taking four different combinations just OB okay so now x value let us assume it is a true 

y value is also true x value true y value is false x value false false and Y value true now x value 

false and Y value also false y value also false let us take a different combinations of data 

so X and Y are the Boolean variables Boolean variables means what which contains only Boolean 

values either true or false now end operator so as I said end or not so these operators also will 

return a Boolean value true or false but when the end operator will return true X and Y I'm using 

this operator between two variables X and Y are what Boolean variables here also Boolean variable 

here also X is a Boolean variable so The Logical operators Works between a Boolean values or 

Boolean variables now if you look at here end operator will return true only if X and Y are 

true okay so here X and Y are true so X and Y will return return true so both are true here x 

should be true y also should be true then only end operator will returns true in all other 

cases it will return false in all other cases it will return false that is a behavior of end 

operator so only one case it will returns true and rest of the cases it will return false so 

and end means what X and Y both should be true then only it will returns true even one of them 

is false it will return false in the second case Y is false third case X is false in the last case 

both are false so it will return False only in one case it will return returns true when it will 

return true if both values are true then only end operator will returns true now come to the 

r r R means either X or Y at least one should be true then it will returns true for example 

in the first case both are true so obviously it will return returns true in the second case X 

is true even though Y is false fine X is true so it will also returns true in the third case Y 

is true so it will returns true only in the last case both are false so here it will return false 

so in three different cases it will returns true only in one case it will return false so how 

exactly this R operator Works r r means either X or Y one should be true at least one should 

be true then only it will returns true in all three cases either X or Y one of it is true so 

it returns true only in the one case both are false so it is rning false that is our operator 

now not not means negation opposite so x value is a true obviously not x value should be false 

and x value is false obviously not x value will be true negation okay and or not so these three 

are called logical operators and uh these logical operators we can use between two Boolean values 

two Boolean values that is the major difference between relational and logical operators both 

are comparison so relational operators also we can use it for comparison logical operators also 

we can use it for comparison but the difference is relational operators we will use for any 

type of data but logical operators we will use only Boolean type of data now this is a simple 

table you can easily understand so notx is an opposite for example X Valu is are true not 

x value should become false suppose x value is equal to false then not x value becomes true 

like this so the opposite of X for example let's say I'm taking one more let say not y okay not 

y now you can just tell me I'm taking not y so here y value is equal to here y value true and 

what could be the not y value if the Y value is equal to true not y becomes false opposite so 

if the Y value is equal to false here y value is equal to false then not Y is equal to True 

opposite okay only one single operator not not means negation okay so simply remember this table 

you can easily understand so I'll keep this table here so these are the logical oper okay now so let us see practical 

example how can we use this logical operators now go to eclipse and uh so logical 

operators only three operators end or not and logical operators always returns either true or 

false and it works between two two Boolean values two Boolean values now I'm taking simple example 

I will Define two variables which are Boolean type of variables let me take Boolean X I'll make it as 

a true Boolean y I'll make it as a false Boolean x equal to True y equal to false because logical 

operators Works between two Boolean variables X is Boolean variable the value of x is true the value 

of y is false now you tell me the output for this system out. print I can say X and Y now what is 

an output of this statement X and Y end operator I'm using true or false obviously it is false why 

it is false because end operator will return true only if both are true but here only X is true Y 

is false so it will return false now instead of end I'm trying to use R operator R now what is 

the return Type R means double pipe you can see pipe symbol on your keyboard you have to type two 

times and what is output of this statement true or false this is true why because XR R means either 

at least one should be true either X or Y even one it is true that is final result is true so in 

this x value is a true so the result is true now you can say not x what is an output of not X and 

what is an output of not y not X and not y x value is a true so not x value should be obviously false 

and Y value is a false so not y value is obviously true right so this is how we can simply use 

logical operators between two Boolean variables now we can see here the last four values false 

true false true okay now I'm going to show you some more examples on Boolean data types now just 

observe you guys can tell me the output here I'm creating one Boolean variable let's say Boolean 

B1 equal to 10 greater than 20 is the statement correct or not can we write statement like this 

Boolean B1 equal to 10 greater than 20 valid or not this statement is valid or not please respond 

is the statement valid or not Boolean B1 equal to 10 greater than 20 is the statement valid or not 

yes it is valid statement why because 10 greater than 20 will return true or false because we are 

using relational operator so greater than we'll compare the two values and return the Boolean 

value so 10 greater than 20 will return return true or false that I'm going to store in another 

Boolean variable so this expression is valid okay now here I'm just trying to print B1 so what is 

an output you will get here true or false false right because 10 is not greater than 20 so 10 

greater than 20 is false so B1 value obviously false now I'm taking one more variable Boolean B2 

and here I say 20 greater than 10 20 greater than 10 now after that I'm trying to print B2 now what 

is an output of this true or false this is true because 20 greater than 10 which is true and will 

be stored in B2 now I can say B2 this is returning true okay now you tell me this output system. B B1 

and B2 are Boolean variables or not yes they are Boolean variables right B1 is a Boolean variable 

B2 is also Boolean variable now can I use logical operators between this B1 and B2 yes we can use 

now I can say B1 and B2 what is an output of this what is B1 B1 contains what a Boolean value false 

it is rning right and what is does B2 contains B2 is also a Boolean variable which is having true 

so B1 is false B2 is true now what is the output of this end operator will return false because 

only one value is true the second one is false so obviously it return return false and now if 

I say B1 R B2 then it will return return true because we are using R of operator so R operator 

will return true if at least one value is true so B1 B2 in B1 and B2 B2 is true so obviously it will 

return return true so we can also use this logical operators between two Boolean values and these 

Boolean values variables can get the output from different type of Expressions okay now I'm going 

to write one simple expression first of all let's run this so the last two false and true we are 

expecting so this is false and true okay now you guys can tell me whether this is valid or not so 

in the first expression I can say 10 less than 20 and in the second expression I'll say 20 greater 

than 10 now tell me what is an output first of all tell me it is valid or not the statement 

is valid or not can we write the statement like this so can we write the statement like this 

first of all I haven't used any variables in this I haven't used any Boolean variables 

I've directly written the expression if I look at this this particular expression will 

return true or false 10 less than 20 true and this will return true or false 20 greater than 

10 true so this is true and this is also true so I'm using end operator between two Boolean 

values so this is true this is also true true and true means the output is obviously true so 

you can write expressions in different ways by using relational and logical operator so this is 

a combination of relational and logical operators okay so we can also combine relational 

and logical operators according to our requirement so now you understood relational 

operators and logical operators how to use relational operators and how to use logical 

operators the major difference is relational or comparison operators we can use with any 

data types but logical operators we can use only with the Boolean data types okay now so let 

us move on to the next one increment and decre ment operators so these are most important Java 

specific operators so before going to them so are you guys clear so far these three operators 

arithmetic relational and logical operators everyone please confirm in the chart in the 

chart window arithmetic relational logical operators okay so now let us move on to the 

next one so these three are special type of operators so mostly everybody everybody is aware 

of these operators but these are little different type of operators yes you can also use relational 

operators with a string data type yes you can use so that though in that case these operators will 

compare the alphabets so every alphabet is having some asky value internally so for example if I 

take a the asky value of a is 76 or 77 so like this for every character in your keyboard there 

is a asky character internally it will maintain so when you compare when I use these operators 

relational operators between the strings basically it will internally compare the asking characters 

and accordingly it will return return true or false okay fine so now let us try to understand uh 

another type of operators so any anyway I'm going to share this one right all the class demos 

so I think I no need to copy this programs in the notepad I think because I'm directly sharing 

these files yesterday also I have already shared these files I think you guys have noticed this 

so I think I this is not needed copy the entire programing the notepad is unnecessary inrease the 

content not needed okay because these programs anyway I'm sharing them so differently and as a 

different files you will get open the files and you can see the right so now let us move on to 

the next one increment and decrement operators most important listen very carefully increment 

Plus+ is called increment operator minus minus is called decrement operator okay guys so this 

is not a final notes guys okay I will also share some of the documents PPS and so on so once you 

finish the Java sessions and at the end of the Java sessions I will give you one PP presentation 

and study material so which contains everything all the noes whatever we discussing during the 

session everything will be part of that noes ppds but not now after completion of java sessions so 

that you can see every Concept in that nodes and document so that will be very very useful so 

don't think this is the final one okay so now let us see how to use increment and decrement of 

so Plus+ is called increment operator minus minus is called decrement operator plus plus is called 

increment operator minus minus is called decrement operator first let us discuss about plus plus 

increment operator how to use increment operator and let us create new class I will name it as 

increment operator taking main method so in this just observe how can we use increment operator 

first so here uh Plus+ is basically called as increment operator Plus+ is called increment 

operator okay suppose I'm taking one variable here in a = to 10 a is an integer variable which 

is having 10 now if I print a value simply I can say a in the print statement I can print a so 

obviously this will print the value of a which is 10 perfect now after printing this a value I want 

to increase the a value by one I want to increase the a value by one so normally how we will write 

an expression if I want to increase a value by One initial values at 10 now I want to add plus 

one so normally how we can create without using increment or nothing just normal expression a = 

to a + 1 this is a normal expression no I'm I'm I'm not asking to assign the data if you say a 

equal to 11 this is also correct but what you are doing here is the old value is replacing with 

the new value 10 is already gone now a becomes 11 I'm not asking to assign the new value I'm 

asking to increase the existing value that means a + 1 when I say A + 1 what will happen 

what is the current value of a 10 10 10 + 1 is what 11 that 11 will be assigned to the a again 

previously a value is 10 now a value becomes 11 so when you print this a value one more time this 

time it will give you 11 right this is how we can increment value by one we can simply say a = to 

a + 1 so a current value of a is 10 10 + 1 11 11 is a new value that again reassigning to the 

same variable whatever variable we are using here after adding one we are reassigning the 

result into the same variable so initially a values a 10 after adding by one it becomes 11 so 

this is a normal way we can increment a value for a variable instead of writing this variable two 

times you can say a equal to a + 1 right you can simply write one single statement which is A++ 

so I can simply say a a ++ I can say A++ that's this is exactly equal to a equal to a + one I 

commented the statement A++ is exactly equal to AAL to A+ 1 so whenever you want to increase 

value by one you can simply use Plus+ operator so when I execute this this time also you will get 

the same thing now we can say 11 so A++ means it is incremented a value by one so when print a 

value after A++ you will get 11 so this is exactly equal to a equal to A+ 1 this is a shortcut in 

Java it is supported increment operators instead of writing the entire expression we can simply 

write A++ okay Plus+ is an increment operator which we can use to increment the value by one 

now in increment operator we have two different aspects one is pre-increment other one is post 

increment pre-increment and post increment just observe this so this is one case this is one 

example case can call it as let a case one instead of AAL to a + 1 I'm directly using A++ 

so which is also incremented value by one and is got printed now let me show you another case 

let's comment this just observe this in interal perspective these are most important just observe 

this case two here again I'm taking same variable in a = to 10 into a = 10 A++ so A++ this will 

increase a value by one right a value becomes 11 now I will store that result in another variable 

let's take one more variable like this so a = to 10 a ++ will become 11 and that I'm storing 

into result after that I'm printing the result value is this clear or not is it valid or not can 

we do like this A++ will increment the a value by one right 11 it becomes 11 that I'm going to 

store in a variable and that I'm going to to print so what is the value are expecting here 

what is an output of the statement what is the output of the statement 11 right so when I run 

this code just see it is still 10 it is still 10 why is it so what happened here so when 

incrementing this value A++ it should become 11 right so the 11 should be assigned to the 

result and it should get 11 here but instead of 11 still we are getting 10 only but when I 

use this A++ in the previous case here we are getting the incremented value so here we got a 

10 and after incrementation we got 11 but what is the difference you have noticed here previous 

case and current case in the previous case after incrementation we are directly printing the a 

value but in this case after incrementation we are storing the incremented value in the variable 

and then we are PR the variable that's only one difference you can notice but still it should 

print 11 but why it is printing 10 so normally what happens is even though it is got printed 

10 whether it is incremented or not first of all if you look at the result it seems it is 

not incremented right but it is incremented a values got incremented even though we are not 

getting here still it is incremented but why we are not getting the incremented value so there is 

a reason for that so whenever you are storing the incremented value in a variable what exactly 

happening here is what is the current value of a 10 right so the 10 will assign to the 

result first after assignment incrementation will happen so after assignment incrementation 

will happen okay so assignment is happened so result value becomes what 10 after assignment 

then incrementation is happened so the result value still it is 10 only why because a Valu is 

directly assigned to the result after assignment then incrementation is happen how we will know 

incrementation is happen or not you can directly print a value then you will know exactly whether 

incrementation is happened or not right so if I print a value obviously you will get 11 you 

will get 11 incremented right by seeing the statement we understood a Val is incremented 

but why it is not printed here because the way of execution is totally different so how it 

is got executing this expression when I store this value in a variable first a value directly 

assigned to the variable after assignment then incrementation is happened so after assignment 

if I print result still we are getting 10 here and if you print a value here we are getting 11 so 

this type of expression is called post increment post increment post increment means what first 

assignment will happen then incrementation is happened post increment so first assignment 

is happened then incrementation is happened that is the reason still we are getting result 

value is 10 so is this clear everyone so why we are getting the same value again after 

incrementation okay so this is called post incrementation this is called post increment 

operator or post incrementation post increment operator okay now let me show you another case 

I hope this case is very clear to everyone so when I say A++ what is happening first a 

value is directly assigned to the result and after that it is incrementing so result 

value Still Remains 10 only right so now let me show you the same expression let 

us see case three okay let me comment this right so case three now just observe 

this in the case three again I'm taking the same variable instead of A++ I will do 

Plus+ a I'm just keeping those Plus+ before the variable so result equal to Plus+ a result 

equal to Plus+ a now just try to remove this now what is an output of this results what 

is an output you are expecting here 10 or 11 so instead of A++ I have written Plus+ a so 

plus plus a is called pre increment of operator so this is called pre-increment pre-increment 

when I use Plus+ operator after the variable which is called post increment when I use Plus+ 

operator before the variable we can call it as a pre-increment so this time when you run this 

code you will get a result 11 so even though if you print a value of a directly you can just 

see the value still till 11 so for both we are getting the 11 so how it is getting 11 here 

how the expression is executing so what is the difference between po increment and pre-increment 

both are incrementation operators but what is the major difference in the pre-increment 

what is happening first it will increment that value after that assignment will happen in 

the post increment first assignment will happen after that incrementation will happen but in the 

pre-increment first incrementation will happen after that assignment will happen so accordingly 

if I look at here first plus plus a means it is already incremented becomes 11 now 11 is assigned 

to the result so when I print the result we got the 11 and again a is already incremented so when 

I print a value also we will get the same result okay so this is a major difference between 

post increment and then pre-increment both are increment operators in both the cases when 

I say A++ or Plus+ a both the cases the value will be incremented by one but when you store the 

result in another variable there is a difference in the pre-increment and post increment okay so 

in the pre-increment what in the post increment first the variable value will directly assign to 

the variable then increment mentation will happen in the pre-increment first incrementation will 

happen and after that assignment will happen so that's the reason we are getting the right value 

here but here first the value directly assign to the variable we are getting result value still 10 

so everyone is understood this please confirm in the chart window increment operator post increment 

pre-increment po increment pre-increment operators okay now the same thing is applicable for 

decrement operator also minus minus if you want to decrease the value by one then 

we use decrement operator so plus plus is for incrementing value by one minus 

minus is for decrementing the value by one okay let's see one more example for 

decrement operator let me close this so let's create a new class I'll name it 

as decrement operator take main method as a finish so same cases again we will see the 

first case it's normal let me take variable in AAL to 10 okay so normally if you want to 

decrease the value by one so what you will do a = to a minus 1 this is a normal expression 

so system. print if I print a value what is an output of the statement a = to a minus one 

so current value of a is what 10 10 - 1 9 so 9 again reassign to the a now the current value 

of a is what nine so this is a normal expression we got a nine same thing we can write by using 

minus minus you can say a minus minus so this is exactly the same as AAL to a - one so when 

you run this this will give you same value n so this is normal case now we will see decrement 

pre- decrement and post decrement so we are not increasing the value here we are trying to 

decrease the value okay A minus minus means it will decrease the value by one so it becomes 

nine initially a value 10 now it becomes nine so this is a normal way we can do now let's see 

the pre pred decrement and post decrement or post decrement and pre- decrement just observe 

this same a equal to into a equal to let's make 100 okay now I can say a minus minus and that I 

can store in a result a minus minus the result I will store in a result variable and then I'm 

printing the result value here and after that I'm trying to print a value also now tell me 

the output of the first statement and second statement 100 or 99 which one you will get here 

when I print result you will still get 100 here 99 so how because it is a post decrement post 

decrement means what what is the post decrement post decrement was first the value will assign 

to the variable aable and then decrement will happen so what is the current value of a 100 

so 100 will assign to the result so here we got 100 after assigning then decrement is 

happen now a becomes 99 so when I print a value you will get a 99 so same formula it is 

also applicable here so this is post decrement first assignment happen then decrement happen so 

190 and now we'll see the pre- decrement another case so just commenting this now case three 

same thing but instead of a minus minus I can say minus minus ausus pred decrement 

now tell me the output of this first statement and second statement so now first 

statement obviously 19 second one is also 19 because first it will decrement happens 

and once it decremented then assignment will happen this is called pre decrement 

pre decrement and here this is post decr okay so now we got both 99 so this is 

called increment and decrement operators plus plus minus minus again in the Plus+ we have 

a post decrement and pre- decrement in minus minus sorry po post increment and pre-increment 

in minus minus we have a post decrement and pre- decrement okay so clear 

everyone increment and decrement operators now so let us see assignment 

operator so far by using increment and decrement operators we are able to increase 

value only by one or we are able to decrease the value only by one right but sometimes 

if you want to increase value more than one or if you want to decrease the value more 

than one then how can we ACH this so plus plus will perform addition right plus plus 

will increment the value by one minus minus will decrement the value by one only one but I 

want to decrease I want to increase the value by five or I want to increase the value by 10 

similarly want to decrease a value by five I want to decrease a value by 10 so how it is 

possible so we can use shorthand operators so these operators we can use so these are the 

operators we can use so let me show you how can we use these operators okay we can call it 

as assignment operators so let me create a new class yes because these are arithmetic 

related operations right because plus minus subtractions these are all related to 

numbers so only arithmetic operators we can do it so how can we increase the characters 

how can we increase the characters and string it doesn't make any sense right so only for 

numbers these operators will work okay so now we'll see assignment operators equal is the 

first most assignment operator that we will assign the value to the variable and other 

than equal to we also have some more types of operator we also call them as a shorthand 

operators okay let me show you something here so what are the assignment operators 

which we have these are all assignment operators these are all assignment operators 

equal to plus equal to minus equal to Star equal to/ equal to modu divion equal to it's very 

simple I'll tell you so I can say in AAL to 10 I want to increase a value by one so normally 

how we will write right a = to a + 1 or A++ but this time I want to increase a value by five 

a value I want increase by five so normally how we will write an expression a = to a + 5 right 

so after that if you print a value then you will get a 15 because initial value of a is 10 now 

here we adding 5 a + 5 10 + 5 15 again reassign to the a now we got a 15 here so here what we 

are doing basically we are increasing a value more than one if it is a one we can directly 

use increment operator plus plus but here if you want to increase more than one you can 

write expression like this or in short way we can write A+ = to 5 this is called shorthand 

assignment operator a plus equal to 5 you don't need to write variables multiple times simply 

can say A Plus equal to 5 plus equal to so this operator will increase a value by five so this 

will also gives you the same result 15 okay so this is a way we can increase value more than one 

okay suppose uh I want to decrease the value by one so this is for incrementation now I want 

to decrease the a value by five decrease then how can we write an expression a = to A Min 

- 5 a = to a minus 5 so a value current value of a is 10 10 - 5 five so the current value of a 

becomes five so when I execute this you will get a five because we decrease a value by five same 

expression you can write like this you can say a minus equal to 5 so not only five you can use 

any number A minus equal to 5 this is another short hand assignment operator a minus equal to 

5 so this will reduce the value by one so now we will get a five same expression you can write 

like this a = A+ 5 you can directly shortcut you can write a plus a plus equal 5 or you can write 

a minus = okay so this is a plus equal to and also minus equal to so star equal to SL equal to 

modular division so how can we use this operators so just observe this so this is one example let's comment this first and at 

the time of practicing you can just remove the comments and do practice okay now say 

example two so when I say in a = to 10 now I want to multiply this a okay let's say uh 

a equal to a star two a equal to a into two so when I print a value what is an output 

of this statement what's an output of this statement a star two 20 right so because current 

value of a is 10 10 into 20 10 into 2 20 20 will again reassign to the a now here we will get a 

20 as an output so this is our expected normal expression AAL to a star okay so instead 

of writing two variables you can simply in shortcut you can write like this a star equal to 

two a star equal to two so a is multiplying with the two and again reassign the new value into 

the same variable so this is another shortcut rate a star equal to two now we got a 20 so this 

is exactly the same as this one similarly slash equal to modular division equal to same thing so 

let's say example okay so I can say in a = to 10 and now I can say if you divide this a by 

two how can we divide a = to a/ 2 this is how we can do right a equal to a/2 a value 10 

10 by 2 5 so what is an output you are getting here by print a value what is an output of this 

so here 10 a value 10 10 divided two what is an output slash slash operator will return the coent 

value which is five so this is division operator and instead of writing AAL to a/2 in shortcut we 

can simply write a slal to 2 short hand operator this will also gives the same result P okay 

same thing you can apply for modular division also so this is example four so instead of Slash 

you can simply say modular division so normally how we will write a equal to a percent 2 so this 

will do the division and remainer will store into the a so here also it will do the same thing so 

when you print a value what is an output you will get here this is mod division Operator 2 5 are 10 

remainder is zero so zero is a r Vector so these are all shortcut operators you can also write 

expression like this nothing wrong in Java okay but if you look at these type of Expressions 

somewhere you should not be confused okay you should understand that expression so that's 

why I'm saying all these things nothing wrong you can use normal expression also if you're 

not familiar with this it will work okay the these are Java specific related operators these 

are all comes under assignment operators so here equal to is a assignment operator it will 

basically assign the value into the another variable and uh I forgot to tell you one more 

operator guys in the relational operators uh we also have a double equal to right so here we 

have seen double equal to means it will compare the two values if both are equal returns to both 

are not equal return false so now you guys can tell me what is the difference between double 

equal to and single equal to double equal to and single equal to what is the difference between 

double equal to operator and single equal to operator dou equal to is a relational operator 

which will be used for comparing the two values and return returns true or false okay whereas 

equal to is a assignment operator which will assign the value into the variable which will 

assign the value into the variable so totally different okay you should not use W equal 

to in every place so whenever you want to assign data use just single equal to whenever 

you want to compare something you just use double equal is this clear everyone difference 

between double equal to single equal to as per Java so double equal to is a relational operator 

comparison operator it will compare the values and returns true or false whereas the single 

equal to will just assign the value into the variable so it is an assignment operator 

fine so now let us move on to the last one conditional or ternary operator question 

mark and colon this is called conditional or ternary operator question mark and colum 

so how to use this question mark and colum so we need to know the syntax first and if you 

know the syntax you can easily use it so tary operator or conditional operator we can also call 

so the syntax is first we specify the variable equal to expression question mark okay and here 

Result One Call and result two so this is a syntax actually so with this syntax we can use tary 

operator question mark colon so here the question mark comes and here the colon comes so this is 

the expression actually the syntax let us see one example how to use this stary operator where 

to use take a new class and I name it as ternary operator so very easy just try to understand this 

so what is the syntax this is the syntax if you know the syntax you can easily use it okay so now 

let me show you one example example one how to use tary operator here I'm taking two variables 

int a = 100 B = 200 int a = 100 b equal to 200 now I want to find which one is largest number 

I just want to print whichever largest or not a is largest or B is largest B is the largest 

number so that we need to find through program I don't want to directly print A and B if I print 

B value I have assumed I have I have decided 200 is a largest value no the program should decide 

according to the condition it will automatically checks which one is the largest number and it 

should print as an output largest number as an output okay basically we have to first compare 

these two whichever is the greatest number that we have to print in the console window that's 

our requirement so by using this tary operator we can achieve this just observe very carefully 

here inter I'm taking one variable Collex just observe the syntax the same syntax I'm just 

replacing it so first thing is what variable so here I'm taking one variable index equal to 

expression expression means what the comparison so here in the bracket I can say 100 okay or I 

can say a B I have taken so let's take a equal to 200 and b equal to 100 anything is fine 

so here I'm taking uh a greater than b this is called expression this is called comparison 

so here we are comparing it so expression then question mark So result one result two is what 

result one I can say a comma result to I can say B and then semicolon so this is a complete 

tary operator expression and after writing this you can just print the value of x then what will 

happen so how exactly it will work so let us try to understand this this is a expression right so 

a value 200 B value 100 so a is a 200 B value is 100 what this expression will return true or 

false a greater than b true or false true so if this expression returns true then the first 

a value will be assigned to the X okay if that Expressions returns true the a value will 

assign to the X if this expression is true this a value will assign to the X then here we 

will get a a value so if I execute this just observe okay let me just run this so you can 

see we got a 200 how we got a 200 here so a greater than b true or false true if it is a 

true a value is assigned to the X what is an a value 200 200 is assigned to the X now we got a 

200 output okay suppose I change that expression a less than b then what will happen expression 

true or false false if the expression is false then the B value assigned to the X and then 

here x will print B value which is 100 like this so how exactly this tary operator works if 

the expression is true then the a value will be return if the expression is false then B value 

will be returned to the so this a value will store in X if the expression is false B value 

stored in the X so according to this if you want to find largest of two numbers how can we do 

it you can say a greater than b if a greater than b a is the largest if a greater than b false then 

B is the largest so like this you can use tenary operator so let me show you one more example 

you guys can understand so when I execute this this will return 100 because B is got return 

into X this is one example let me take another example so this time you guys can tell okay let me comment this now example two just 

observe how I writing the statement first tell me it is valid or not in x equal to X is a variable 

okay in the expression I'm writing 1 equal to 1 question mark 100 coln 200 okay now I'm printing 

the value of x now tell me output of the X first of all let me tell me this statement is valid 

or not is is the statement valid or not yes or no line number 20 the statement is valid or 

not yes obvious it is valid why because X is a variable 1 equal to one is an expression this 

will return true or false so that expression is always written true or false here which one 

it will return 1 equal to one means true right so if it is a true 100 will assign to the X if 

the expression is false 200 will assign to the X okay now what is an output of X here obviously 

100 because condition is true expression is true so 100 is assigned to the X then we got an X 

so this expression is perfectly correct okay now let me write another type of expression 

in x equal to my expression is 1 = 2 question mark okay question mark uh I can say 200 col 

100 okay now tell me the value of x is what what is an x value 200 or 100 obviously it 

is 100 why because this expression returns false if the expression return false the 100 

will assign to the X so the x value is 100 x value is 100 perfect okay so guys now you 

understood how exactly this tary operator is working yes I will show you we can also 

use it for Strings also yes so first of all have you understood how exactly this tary 

operator is working first it will check the expression if it is a true the first value 

assigned to the variable if it is a false the second value assigned to the variable that's 

how it will work okay so I will show you more examples you will understand this better so now 

my requirement is this is example two so example three so here uh I will take one variable person 

age let's say 30 I want to check this person is eligible for o or not I want to check this person 

is eligible for o or not through ternary operator I want to print eligible or not eligible 

simply based on the age so my condition is if the person age is greater than or equal to 18 

he's eligible is less than 18 he's not eligible that's a condition so how can we achieve this 

using tary operator very simple first create a variable called result and what would be 

the expression here when he is eligible for OT if the AG is greater than or equal to 18 

eligible for so here I'm taking that variable person age person age okay greater than or equal 

to 18 this is the expression person age is the variable I have already defined above so get 

this is a condition expression question mark if this expression is true if this expression is 

true what is an output I should get eligible so in the double quotations you can put because 

this is a string right eligible colon if the expression is false then what we have to get not 

eligible semicolon okay so now if you print result result is a string variable now why because this 

will return eligible or not eligible this is a string value so I have to take this variable as 

a string now tell me what is an output of this eligible or not eligible eligible why because 

I have taken person is 30 so person is greater than equal to 18 the expression is true if it 

is a true this part will store in the result if it is false not eligible will store so when I 

execute he is eligible suppose let us make this as 15 now the condition become false as soon as 

the condition become false then not eligible will assign to the result so when I execute this 

you will get not eligible okay so this is how we can use tary operator we can also achieve this by 

using conditional statement if else conditions so in the next classes we will discuss that so this 

is called tary operator okay so with this we have completed all types of operators arithmetic 

operators relational or comparison operators logical operators increment and decrement again in 

increment decrement we have pre and post increment and decrement assignment or shorthand operators 

and conditional or tenary operators so these are the operators most commonly used in Java okay so 

again all these operators again divided into three categories three categories okay so one category 

is called unary operators unary operators binary operators tary operators okay ternary operators now what is 

this actually what is unary what is binary what is ternary unary operators means those 

operators we can use with single variable the unary operator means those operators we can 

use with the single variable now can you tell me what are the operators here we can use with 

single variable can you just tell me what are the unary operators unary operators means the oper 

it can be any type of operator which comes under any category but those operators we can use with 

single variable just with single variable we can use those operators so what are those operators 

we can see here just tell me in individually unary operators just tell me symbols so what are the 

operators unary means those operators we can use with a single variable remember this term Single 

variable see arithmetic operators if you want to use at least two variables we required right 

so when you can perform addition at least two variables you requir when you perform subtraction 

when you can perform Division and modular division at least two variables we required right so they 

not comes under unary operators so unary means only one we should able to apply that operator 

only on single variable so such type of operators we call it as a unary operators now tell me what 

are the unary operators Plus+ is a unary operator right just single variable we require minus minus 

is also unary operator because single variable be required same thing plus equal to minus equal 

to okay star uh star equal to slash equal to and modular division equal so to use these operators 

we need only just one single variable is enough right or wrong single variable is enough or not 

to use these operators plus plus minus minus plus minus plus star equal to SL equal to so to use 

these operators just one variable is required so these are all comes under unary operators 

okay even equal to also single equal to okay and not these operators we can use with single 

variable so we can call them as unary operators now binary operators tell me what are the binary 

operators at least two variables we should have so if we want to use these operators at least 

two variables we should have so what are those operators what are those two variables you must 

have two variables if you want to use binary operators all arithmetic operators we comes under 

binary operators because two variables at least we required similarly all relational operators 

also comes under binary because at least two values we require to compare right two values 

at least we need to compare so all relational operators comes under binary operators next what 

next arithmetic operators B arithmetic operators relational operators what else logical operators 

these two comes under binary but not comes under binary not is comes under unary because only 

one single variable is required two variables not required but if you want to use end or at 

least two variable two Boolean variables are required right so end or also comes under binary 

operator right so these are all comes under binary operators at least two variables we required to 

use these operators now finally we have only one ternary operator three variables required at least 

three variables three uh variables required which is tary operator colum same in this three 

variables are required so three variables in the sense what if I look at this this is one 

this is two this is three okay three things are required if I look at the expression this is one 

variable this is second this is thir if you have these three then only we can use tary operator 

right so tary means three binary means two unary means one so unary operators we can use with 

single variable by binary operators we can use with two variables ternary operator we can use 

with three variables okay so these are all about operators concept so these are all fundamental 

very basic very fundamental concepts you have to practice a lot so if you're not practicing these 

things upcoming sessions or upcoming Concepts you cannot understand the coming sessions we 

will discuss conditional statement looping statement so many things so many examples these 

are all fundamentals if you not understood this you cannot understand further Concepts so you 

have to practice this multiple times you need to aware of this okay so clear everyone please 

confirm in the chat window once again operators concept right so let us stop here for today's 

session and do this practice and I will give one assignment based on this topic yesterday topic 

and today's topic yesterday we discussed about variables and data types and today we discussed 

about operators now based on that I will give you one small assignment you guys can try this I will 

also provide the solution for this but this is a little different I will tell you what exactly it 

is swapping of two numbers very popular program but I'm expecting to do this the different I'll 

tell you how can we do it swapping of two numbers what is swapping so what is swapping so let me 

just give you logic you guys can try so swapping means the interchanging of values between two 

variables for example let's say initially I'll take a value 10 B value 20 so before swapping so 

before swapping the a value is a 10 B value is a 20 so after swapping okay after swapping I should 

get a value 20 b value 10 so these values should be interchanged that is called swapping you have 

to achieve this okay so how can we achieve this so most of the people will use a temporary variable 

a simple logic they will use for example I have let's say three containers let us say this is a 

this is B and let us take C also C is a temporary variable it doesn't have any value now initially 

a value 10 B value 20 now how can we interchange these two values so I have to get 20 into the a 

similarly I want to get 10 into the B so let us use a temporary variable called C take another 

variable called C now what I will do first step I will assign a value into the C okay then what 

will happen happen a value into the C now C value becomes 10 second this is the first step second 

step I will assign B value into the a b value into the the Second Step so I will assign B value into 

the a then what happens the 20 will assign to the a now a value will replace with the 20 then third 

step I will assign the C value into the B third step now if iend C value into the B then what will 

happen C value is current value of C is what 10 10 will assign to the B now this will over replaced 

with the 10 now after executing these three statements now what is the current value of a 20 

current value of B 10 the values are interchanged or not yes this is called swapping okay so by 

writing these three statements initially you take a value and B value something after execution 

of these three statements if I print a value and B value the swapping is done okay this is the 

most common very popular solution everywhere you can see this but I don't want to do like this 

without using temporary variable I don't want to use this temporary variable so without using 

this temporary variable just by using operators arithmetic operators okay just by using AR Artic 

operators without using any temporary variable just by using arithmetic operators you can do 

that swapping technique swapping of two numbers without using temporary we so you guys can try 

this think about this logic how can we do this and if you Google it you can find the solution 

in many places there are so many solutions are there without using temporary variable almost 

four to five different solutions are there but I ask you guys can guess and you guys can check 

the logic and accordingly you can try this and for the solution I will share a small video here 

I will just share small video link here you can just go through that video and you can understand 

the solution I have given almost three to four different ways we can do the swapping okay so you 

guys can use whatever you want that is up to you don't ask me now okay you can use any way other 

than the temporary variable there are four to five different ways are there you can find out 

at least one or two ways you guys can at least one okay any approach is fine but other than using 

temporary variable so don't use temporary variable other than using temporary variable that approach 

you can try any other approaches you can use plus minus operators you can use star/ operators a 

different type of arithmetic operator you can can use combination of those operators but you 

don't want to create any other variables Just A and B only two variables you have to create and 

you should able to swap no temporary variable without temporary variable Just A and B only two 

variables we have to create and we have to do the swapping so here I have given the link this is 

a link you can just go through this link okay and uh I have explained all the approaches in 

this video first you try yourself okay and if you're not able to get the logic then go to the 

video you can understand that logic and you guys can Pro that okay so here in the notes I provided 

this link solution you guys can refer this this is a assignment for today's session and slowly I'll 

try to increase assignments also and day by day because once you start learning more Concepts 

I will try to give more number of assignments fine that's it so this is the topic for today and 

tomorrow we'll continue with another topic okay