JavaScript for Beginners
About Lesson

do...while Loop is a control flow statement that executes a block of code once, and then repeats the execution as long as a specified condition evaluates to true.


Syntax of a do…while Loop

The syntax of a do...while Loop in JavaScript is as follows:

do {
   // code to be executed
while (condition);


  • Condition: This is a Boolean expression that is checked after each iteration of the loop. If it evaluates to true, the loop continues; if it evaluates to false, the loop ends.


Example of a do…while Loop

Here’s a simple example of a do...while Loop that prints the numbers from 1 to 5:

let i = 1;
do {
} while (i <= 5);


In this example, i is initialized to 1, the console.log(i) inside the loop will print the number, and i is incremented by 1 at the end of each loop iteration. The condition checks if i is less than or equal to 5 after the loop has run once.


The do...while Loop is a unique tool in JavaScript, that allows you to ensure that a block of code is executed at least once before the condition is checked. It’s a fundamental concept that’s widely used in programming, so understanding how it works will greatly enhance your JavaScript coding skills.