TypeScript do while

Summary: in this tutorial, you will learn how to use the do...while statement to create a loop that runs until a condition evaluates to false.

Introduction to TypeScript do…while statement

The following shows the syntax of the do...while statement:

do {
    // do something
} while(condition);
Code language: TypeScript (typescript)

The do...while statement executes statements in its body surrounded by the curly braces ({}) until the condition is false.

The do...while statement always executes its loop body at least one.

Unlike the while statement, the do...while statement evaluates the condition after each loop iteration, therefore, it is called a post-test loop.

TypeScript do…while statement example

The following example uses the do...while statement to output numbers from 0 to 9 to the console:

let i = 0;

do {
    console.log(i);
    i++
} while (i < 10);
Code language: TypeScript (typescript)

Output:

0
1
2
3
4
5
6
7
8
9
Code language: TypeScript (typescript)

How it works:

• First, declare a variable i and initialize it to zero before entering the loop.
• Then, output i to the console, increment it by one, and check if it is less than 10. If it is, repeat the loop until i greater than or equal 10.

Summary

• Use the do...while statement to create a loop that runs until a condition evaluates to false.