Java program for do while loop

Program Description

Write a java program for do while demo. In this page, we will write a simple java program to demonstrate the do-while-loop.

Syntax

General syntax of the do-while is shown below. The expression evaluation is done after the loop. So the do-while is executed at least once irrespective of the loop condition.

do

{

//statements

} while (Boolean_expression);

Java Program

Lets write a simple program to display a menu to user and display it until user choose to quit the loop. We will make use of the do while loop in the program.

import java.util.Scanner;
//------------------------------------
// DoWhileDemo.java
// www.TestingDocs.com
// Program to demo do while loop
//-------------------------------------
public class DoWhileDemo {
  public static void main(String[] args) {
    int choice; // to take choice input
    Scanner keyboard= new Scanner(System.in);
    do {
      System.out.println("~~~~~~~~ Menu ~~~~~~~~");
      System.out.println("1. Option 1");
      System.out.println("2. Option 2");
      System.out.println("3. Quit");
      System.out.println("Enter choice =");
      choice=keyboard.nextInt();
      if(choice==1) {
        System.out.println("User entered 1");
      }
      if(choice==2) {
        System.out.println("User entered 2");
      }
    }while(choice != 3);
  }
}

 

Program Output

~~~~~~~~ Menu ~~~~~~~~
1. Option 1
2. Option 2
3. Quit
Enter choice =
1
User entered 1
~~~~~~~~ Menu ~~~~~~~~
1. Option 1
2. Option 2
3. Quit
Enter choice =
2
User entered 2
~~~~~~~~ Menu ~~~~~~~~
1. Option 1
2. Option 2
3. Quit
Enter choice =
3

Screenshot