setinterval()

The setInterval() method is used to execute a function repeatedly at specified time intervals.

Syntax

The setInterval() function is used to execute a function repeatedly at a specified interval (delay).

intervalID = setInterval(function, delay, arg0, arg1, /* … ,*/ argN)

setInterval() takes the following parameters:

• The function to be executed or, alternatively, a code snippet.
• The delay in milliseconds between each execution. This parameter is optional and if not provided defaults to 0.
• Optional additional arguments (arg0, arg1 … argN), which are passed to the function once the timer expires.

After setInterval() is executed, the function argument is executed only after the given delay.

It returns a numeric, non-zero value as intervalID of the timer created by the call to setInterval(). This intervalID value can be passed to clearInterval() to cancel the interval.

Example

Following code outputs “Hello” 3 times to given number each second

let i = 1; // Initial count
const iMax = 3; // Max count

// Function passed to `setInterval()` method
function sayHello() {
  console.log('Hello number ' + i);
  i = i + 1;
  if (i > iMax) {
    clearInterval(intervalID); // Canceling the repeating action of the `setInterval()` method
  }
}

const intervalID = setInterval(sayHello, 1000); // Calling the `setInterval()` method

Expected output:

Hello number 1
Hello number 2
Hello number 3