Node.js Tutorial - Node.js setTimeout setInterval


setTimeout sets up a function to be called after a specified delay in milliseconds.

The following code shows a quick example of setTimeout, which calls a function after 1,000 milliseconds (one second).

setTimeout(function () {
    console.log('timeout completed'); 
}, 1000); 


Similar to the setTimeout function is the setInterval function.

setTimeout only executes the callback function once after the specified duration.

setInterval calls the callback repeatedly after every passing of the specified duration.

The following code prints out second passed after every second.

setInterval(function () { 
    console.log('second passed'); 
}, 1000); 


Both setTimeout and setInterval return an object that can be used to clear the timeout/interval using the clearTimeout/clearInterval functions.

The following code demonstrates how to use clearInterval to call a function after every second for five seconds, and then clear the interval after which the application will exit.

var count = 0; 
var intervalObject = setInterval(function () { 
        console.log(count, 'seconds passed'); 
        if (count == 5) { 
    }, 1000);