Lexical This

new.js

//ES2015
function VideoGame(){
  this.title = "Uncharted";
  this.version = 3;

  setInterval(() => {
    console.log(this.title + " " + this.version++); // |this| properly refers to the VideoGame object
  }, 5000);
}

prior.js

//prior ES2015
function VideoGame(){
  var me = this;
  me.title = "Uncharted";
  me.version = 3;

  setInterval(function() {
    // The callback refers to the `me` variable of which
    // the value is the expected object.

    console.log("1:", this); //Context is Window
    console.log("2:", me); //Context is VideoGame object
    
    console.log(me.title + " " + me.version++);
    
  }, 5000);
}