function looping js every few seconds code example

Example 1: run for loop every second js

var time = 1;

var interval = setInterval(function() { 
   if (time <= 3) { 
      alert(time);
      time++;
   }
   else { 
      clearInterval(interval);
   }
}, 5000);

Example 2: js loop every x seconds

(function loop() {
  setTimeout(function () {
    // execute script
    loop()
  }, 9000); //9000 = 9000ms = 9s
}());