lopping java in hindi | looping statement in java in hindi

Looping Statement in Java

Looping statements allow the programmer to execute some group of statement repetitively multiple times.

Control goes inside the body of the loop if the condition is true otherwise goes outside of looping block. The main difference between decision making statements and looping statement is decision making statement execute once alike looping statements executes several times.

There are two types of loop

1.    Entry control loop (while loop and for loop)

2.    Exit control loop (do … while loop)

Entry control loops are the loop in which condition is tasted at the beginning of the loop.

Exit control loops are the loop which condition is tasted at the end of the loop.

Do … while is an exit control loop. For and while are entry control loop.

Note : Exit control loops are executed at least once in their lifetime.

Advantages of looping :

• Reduce the memory consumption.
• Reduce the length of the code.
• No need to write same code again to execute several times

Following are the types of looping statements

• while loop
• do … while loop
• for loop
• nested loops

   1.    While loop

While loop is an entry control looping statement that allows code to be executed until the boolean condition is true.

You can also call while loop as a repeating if statement.

Syntax :

...

//Assignment of counter variable

while(condition)

{

//body of loop

//increment or decrement of variable

}

...

Flowchart :

  

while loop

 

                                                    while loop

Example :

class WhileLoop{

            public static void main(String args[]){

                        int i=0; // Assignment of counter variable

                        while(i<10){

                                     //This loop will be executed 10 times.

                                     System.out.println(i);

                                     i++; //increment of counter variable

                        }

            }

}

Output :

C:\workspace>notepad WhileLoop.java

C:\workspace>javac WhileLoop.java

C:\workspace>java WhileLoop

0

1

2

3

4

5

6

7

8

9

C:\workspace>

    1.    Do … while loop

Do … while is an exit control looping statement which is also used to execute a block of instructions several times. This loop is executed at least once in its lifetime whether the condition is true or false.

Syntax :

//Assignment of counter variable

do{

//body of statement

//increment or decrement of counter variable

}

while(condition); //You must put semicolon here

Flowchart :

 

java looping

                                   do while loop

Example :

class DoWhileLoop{

            public static void main(String args[]){

                        int i=0; // Assignment of counter variable

                        do{

                                     //this body will be executed at least once

                                     System.out.println(i);

                                     i++; //increment of counter variable

                        }

                        while(i<10);

            }

}

Output :

C:\workspace>javac DoWhileLoop.java

C:\workspace>java DoWhileLoop

0

1

2

3

4

5

6

7

8

9

C:\workspace>

Note : You need to put a semicolon at the end of the do … while statement.

   

    1.    For loop

For loop is an entry control loop which works same as the other two loop but its syntax is different. In other two loop counter variable is declared outside the body of the loop.

Here, the counter variable is declared within for loop itself but the counter variable is declared and assigned by initial value only once.

Increment and condition checks will be done multiple times.

Syntax :

for(init; condition; increment or decrement){

//body of for loop

}

Flowchart :

java lopping statement

 

Example :

class ForLoop{

            public static void main(String args[]){

                        for(int i=0;i<10;i++)

                        {

                                     System.out.println(i);

                        }

            }

}

Output :

C:\workspace>javac ForLoop.java

C:\workspace>java ForLoop

0

1

2

3

4

5

6

7

8

9

C:\workspace>

   1.    Nested loops

The concept of a nested loop is as same as nested decision-making statement. One loop can contain another looping statement.

Example :

class NestedLoop{

            public static void main(String args[]){

                        int j;

                        for(int i=0;i<5;i++)

                        {

                                     j=1;

                                     while(j<=i)

                                     {

                                                 System.out.print("*");

                                                 j++;

                                     }         

                                     System.out.println();

                        }

            }

}

Output :

C:\workspace>javac NestedLoop.java

C:\workspace>java NestedLoop

*

**

***

****

C:\workspace>