do-while Loop

In Java, the do-while loop is a variation of the while loop. The key difference is that the do-while loop guarantees that the block of code is executed at least once, even if the loop condition is initially false. The basic syntax of the do-while loop is as follows:

do {
    // Code to be executed
} while (condition);

Example:

public class DoWhileLoopExample {
    public static void main(String[] args) {
        int i = 1;

        do {
            System.out.println(i);
            i++;
        } while (i <= 5);
    }
}

In this example:

• int i = 1; initializes a loop control variable i to 1.
• The do block contains the code to be executed. In this case, it prints the value of i.
• i++; increments the value of i after each iteration.
• The while (i <= 5); is the loop condition. The loop will continue as long as the condition is true.

The output of this program will be:

1
2
3
4
5

Even if the condition is initially false, the code inside the do block is executed at least once before checking the condition. This makes the do-while loop suitable when you want to ensure that a certain block of code runs at least once, regardless of the initial condition.

Example with Initially False Condition:

public class DoWhileExample {
    public static void main(String[] args) {
        int i = 5;

        do {
            System.out.println("This will be printed at least once.");
        } while (i < 3);
    }
}

In this case, the message inside the do block will be printed once, even though the condition is initially false.