TypeScript - setTimeout example

In this article, we would like to show you how to use setTimeout in TypeScript.

Quick solution:

let x: number = 0;

const action = (): void => {
  console.log(x);
  if (++x < 3) {
    setTimeout(action, 1000);
  }
};
setTimeout(action, 1000);

setTimeout is a method that sets a timer that executes a function or specified piece of code after the timer expires.

Basic version of setTimeout takes in two arguments:

• a function (or piece of code) to be executed,
• delay - time in milliseconds the timer should wait before the function or code passed in as a first argument is executed.

You can also pass additional arguments which will be passed through to the function.

Note:

You can find more information about setTimeout and passing arguments to the method - here.

1. Basic setTimeout example

Below we create a function with setTimeout inside that calls the function three times every 1 second.

Arguments passed:

• function: action,
• delay: 1000 (1 second).

Runnable example:

let x: number = 0;
const action = (): void => {
  console.log(x);
  if (++x < 3) {
    setTimeout(action, 1000);
  }
};
setTimeout(action, 1000);

Output:

0
1
2

2. setTimeout with additional arguments example

Below we create a function that takes in two arguments which we will pass through the setTimeout as additional arguments after function and delay.

Runnable example:

const action = (arg1: string, arg2: string): void => {
  console.log(arg1 + arg2);
};

console.log('setTimeout will display text in 3 seconds...');
setTimeout(action, 3000, 'Hello ', 'world!');

Output:

setTimeout will display text in 3 seconds...
Hello world!