Answers for "use this in set timeout"

javascript set timeout

setTimeout(function(){
 	console.log("hello");
}, 3000); //wait for atleast  3 seconds before console logging

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();