Overview
In this tutorial, we will learn the do-while loop statement. In this loop statement, the loop condition is checked at the end of the loop.
Java while Loop
https://www.testingdocs.com/java-while-loop-statement/
do while Loop
This loop checks the loop condition after executing the loop statements. (post-check loop control). The loop statements will execute at least once even if the loop condition evaluates to false.
The do-while loop is guaranteed to execute the loop statements at least once. So, this loop is ideal for menu-based user programs. We can display the application menu in the loop and let the user decide the flow of the program.
do
{
// loop Statements
}
while(boolean loop condition);
Example
In the below example, we will use a do-while loop to display a menu to the user. The program takes actions based on the user input to the program.
public class DoWhileLoopDemo {
public static void main(String[] args) {
int choice = 0;
Scanner keypad = new Scanner(System.in);
do {
System.out.println("--- Menu ---");
System.out.println("1.Task1");
System.out.println("2.Task2");
System.out.println("3.QUIT");
System.out.println("Enter choice:");
choice = keypad.nextInt();
if(choice == 1)
System.out.println("Perform Task1
for user.");
if(choice == 2)
System.out.println("Perform Task2
for user.");
}while(choice == 1 || choice == 2);
}
}
Sample Program Output
— Menu —
1.Task1
2.Task2
3.QUIT
Enter choice:
1
Perform Task1 for user.
— Menu —
1.Task1
2.Task2
3.QUIT
Enter choice:
2
Perform Task2 for user.
— Menu —
1.Task1
2.Task2
3.QUIT
Enter choice:
3
The loop will run many times as per the user’s choice. The loop will run if the user choice is 1 or 2. The loop will terminate for any other user option.
—
Java Tutorials
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https://www.testingdocs.com/java-tutorial/
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