JavaScript - setInterval() function example

In this article, we would like to show you how to use setInterval() in JavaScript.

Quick solution:

// ONLINE-RUNNER:browser;

setInterval(() => {
    console.log('This will be displayed every 1000ms (1s).');
}, 1000);

or:

// ONLINE-RUNNER:browser;

const handle = setInterval(() => {
    console.log('This will be displayed every 1000ms (1s).');
}, 1000);

clearInterval(handle);  // stops intervals

1. Documentation

Below we present some practical examples for better understanding.

1. Simple setInterval example

In this example, we create and call a simple function that displays some text every second.

Runnable example:

// ONLINE-RUNNER:browser;

setInterval(() => {
    console.log('This will be displayed every 1000ms (1s).');
}, 1000);

2. Calling setInterval the specified amount of times

In this example, we create a function with setInterval that counts to 5 every second.

Runnable example:

// ONLINE-RUNNER:browser;

let i = 0;
let interval = setInterval(() => {
    console.log(i + 1);
    if (++i === 5) {
        clearInterval(interval);
    }
}, 1000);

3. Custom setInterval

In this example, we create customSetInterval that takes in three arguments:

• count - how many times we want to call the callback function,
• delay - time between callback function calls,
• callback - a function to be called.

Runnable example:

// ONLINE-RUNNER:browser;

const customSetInterval = (count, delay, callback) => {
    var i = 0;
    var interval = setInterval(() => {
        callback(i, count);
        if (++i === count) {
            clearInterval(interval);
        }
    }, delay);
};


// Usage example:

const foo = (index, count) => console.log(`${index + 1}/${count} Some text here ...`);

customSetInterval(5, 1000, foo);