whenever alert came setInterval fails code example

Example 1: javascript run every 5 seconds

const interval = setInterval(function() {
   // method to be executed;
 }, 5000);

clearInterval(interval); // thanks @Luca D'Amico

Example 2: js setinterval vs settimeout

var intervalID = setInterval(alert, 1000); // Will alert every second.
// clearInterval(intervalID); // Will clear the timer.

setTimeout(alert, 1000); // Will alert once, after a second.