Do-While Loop

A do-while loop is a slight variant of a while loop. It checks its condition at the end of the loop rather than at the beginning, so it will always execute the body at least once, even if its condition is initally false. Compare the following code and flowchart to the while loop flowchart to see the difference:

int x = 0;
do {
    x = x + 1;
    println(x);
} while (x < 100);

The structure of a do-while loop is similar to a while loop, with two small differences:

• The loop begins with the do keyword and no condition
• We still use the while keyword, but after the loop's body, and there is a semicolon after the condition

The do-while loop exists purely for convenience, and chance are you'll rarely use it. It's worth using when it makes your code clearer or more concise, but you can always use a standard while loop to accomplish the same thing.