ES6 Basic Class example

JavaScript

class SomeClass {
   constructor() {
     this.asInstance = function() { console.log(this); }

     var looseFunction = function() { console.log(this); }
     const arrow = () => console.log(this);

     this.asLooseFunction = function() { looseFunction(); }
     this.asArrowFunction = function() { arrow(); }
   }

   asPrototypeMethod() { console.log(this); }
}

var test = new SomeClass();
test.asLooseFunction()   // => undefined 
test.asInstance();       // => SomeClass {}
test.asArrowFunction()   // => SomeClass {}
test.asPrototypeMethod() // => SomeClass {}