Java Do While Loop

The do-while loop in Java is a control structure that repeatedly executes a block of code as long as a specified condition is true. It is similar to the while loop, but the key difference is that the do-while loop guarantees that the code block is executed at least once, even if the condition is initially false. Here’s the basic syntax of the do-while loop in Java:

do {
    // Code to repeat
} while (condition);

• The code block inside the do block is executed first, and then the condition is evaluated.
• If the condition is true, the loop continues and the code block is executed again.
• If the condition is false, the loop terminates.

Here’s an example of using a do-while loop to print numbers from 1 to 5:

public class Main {
    public static void main(String[] args) {
        int i = 1;
        do {
            System.out.println(i);
            i++; // Increment the loop control variable
        } while (i <= 5);
    }
}

In this example:

• int i = 1 initializes the loop control variable i to 1 before entering the loop.
• The code block inside the do block is executed first, printing the value of i.
• i++ increments the loop control variable i by 1 after each iteration.
• i <= 5 is the condition, specifying that the loop will continue as long as i is less than or equal to 5.

The loop will execute five times, printing the numbers 1 to 5, just like in the while loop example. The key difference is that with a do-while loop, you are guaranteed to execute the code block at least once before checking the condition.

The do-while loop is useful when you want to ensure that a particular action is performed at least once, regardless of the initial condition.