Do-While Loop in Java

Do-While loop is similar to the while loop.when a set of statements have to be repeatedly executed at least once untile a certain condition is reached. When we do not know exactly how many time a set of statement have to be repeated do while can be used.

How Do-While Loop Works in Java.

• step 1:-
  The initialization statement is executed first
• step 2:-
  Then, the test expression is evaluated. If the test expression is evaluated to false, then the while loop gets terminated and the control comes out of the while loop.
• step 3:-
  if the test expression is evaluated to true,The statements defined inside the while loop will repeatedly execute until the given condition fails.
• step 4:-
  After successful execution of statements inside the body of the while loop, the update expression is executed.
• step 5:-
  Again the test expression is evaluated.

   

    
import java.util.Scanner;

public class Main 
{
  public static void main(String[] args) 
  {
    // Take input from the user
    // create an object of Scanner class
    Scanner sc = new Scanner(System.in);
	   
    int sum = 0;
    int num = 0;

    // do...while loop continues 
    // until entered number is positive
    do {
      // add only positive numbers
      sum += num;
      System.out.println("Enter a number");
      num = sc.nextInt();
    } 
    while(num >= 0); 
	   
    System.out.println("The sum of entered positive numbers is " + sum);
    sc.close();
  }
}