Do while loop java

Hey guys!! Welcome to flower brackets blog. In this post we are going to learn do while loop java.

Also read – java if else

Java do while loop executes the body even before the test condition. So it’s guaranteed to execute the body at least once.  Here’s the syntax,

Syntax :

do
{
   statement(s);
}
while(expression);

do while loop java

In the above flow diagram first statements inside do while loop execute then condition gets evaluated. If condition is true then control gets shifted inside “do” else jumps outside do while statement.

Here’s an example,

public class DoWhileDemo
{
   public static void main(String[] args)
   {
      int x = 1;
      do
      {
         System.out.println(x);
         x++;
      }
      while(x <= 5);
   }
}

Output:

1
2
3
4
5


Infinite do-while

An infinite do while loop is a loop that will execute endlessly because loop’s expression is always true. Here’s an example,

Syntax

do
{  
   // code goes here
}while(true);

public class InfiniteDoWhileDemo 
{
   public static void main(String[] args) throws InterruptedException
   {
      do
      { 
         System.out.println("Start do while");
         System.out.println("End do while");
         Thread.sleep(3 * 1000);
      }while(true);  // press ctrl+c to exit 
   }
}


Similarly we can iterate an array using do while loop,

class DoWhileLoopDemo 
{
   public static void main(String args[])
   {
      int arrNum[] = {2,4,6,8};
      int a = 0;
      do
      {
         System.out.println(arr[a]);
         a++;
      }while(a < 4);
   }
}

Output:

2
4
6
8

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