set time intrval to check in each second code example

Example 1: js do every x seconds

window.setInterval(function() {
  // do stuff
}, 1000); // 1000 milliseconds (1 second)

Example 2: how to do a function after a set interval js

function sayHi() {
  alert('Hello');
}
//Do a function at a set interval continuously
setTimeout(sayHi, 1000);
//Do a function once after a set interval
setTimeout(sayHi, 1000);