new Binding

This is part of the series this keyword in Javascript

this — most confused mechanism in Javascript

Javascript has “new operator” which may seem like new in Java.
Hmm, its not like the constructors in other languages. Then what is a constructor in JS?

• functions called with new operator
• not attached to any class
• not instantiation

When function is invoked with new, behind the scene below things happen:-

• new object is created( constructed).
• newly constructed object is [[Prototype]] linked
• newly constructed object is set as the this binding for that function call.
• Unless function returns its own alternate object, the new invoked function call will automatically return the newly constructed object.

function newBinding(a){
 this.a = a;
}
var newlyCreated = new newBinding(10);
console.log(newBinding.a)//10;
calling new in front of newBinding, we have constructed a new object and set that new object as the "this" for the call of newBinding.