How to inherit an Object in JavaScript

 We can use the
prototype chain to implement the inheritance of methods from a super class.

1. The method most people use:

   function inherit(sub, supper){    var subProto = sub.prototype = new supper();    subProto.constructor = sub;}

   Note: this will always call the supper's constructor and it is just a waste in some way.
    
   

2. The method not really inheritance:

   function inherit(sub, supper){    var subProto = sub.prototype, supProto = supper.prototype;    for(var i in supProto){        if(!subProtp[i]) subProto[i] = supProto[i];    }}

   Note: the result of new Sub() instanceof Supper is false. 

3. The method derives from method 1:

   function inherit(sub, supper){    var subProto = sub.prototype;    subProto = Object.create(supper.prototype);    subProto.constructor = sub;}function inherit(sub, supper){    var subProto = sub.prototype;    var F = function(){};    F.prototype = supper.prototype;        subProto = new F();    subProto.constructor = sub;}

   
   

4. The method
   simplest but IE doesn't support:

   function inherit(sub, supper){    sub.prototype.__proto__ = supper.prototype;}