is settimeout part of javascript code example

Example 1: javascript run something after x seconds

setTimeout(function(){
  location.reload();
}, 3000); //run this after 3 seconds

Example 2: javascript this in settimeout

function func() {
  this.var = 5;
  
  this.changeVar = function() {
    setTimeout(() => { //Don't use function, use arrow function so 'this' refers to 'func' and not window
      this.var = 10;
    }, 1000);
  }
}

var a = new func();
a.changeVar();