How do you do inheritance in JavaScript without sharing the same instance of the super class between all instances of the sub class?

Question

I noticed that every tutorial on how to do JavaScript inheritance does this:

SubClass.prototype = new SuperClass();

But this will create a single instance of the super class and share it among all the instances of the sub class.

The problem is that I would like to pass arguments to the super class constructor which originate from arguments passed to the sub class.

In Java this would be done like this:

class SubClass extends SuperClass {
  public SubClass(String s) {
    super(s);
  }
}

I tried doing something like this:

function SubClass(args) {
  this.constructor.prototype = new SuperClass(args);
}

But this will not work. So is there a way to do this in JavaScript?

Answer 1

This is how I have always done it.

// Parent object
function Thing(options)
{ 
    //do stuff
}

Thing.prototype.someMethod = function(){
    // some stuff
   console.log('hello');
}

// child object which inherits from the parent
function OtherThing(options)
{       
    Thing.call(this, options);
    // do stuff for otherthing
}

OtherThing.prototype = new Thing();

OtherThing.prototype.someMethod = function(){
   // call things original function
   Thing.prototype.someMethod.call(this);

   // now do anything different
   console.log('other thing says hi');
}


var testObj = new OtherThing();
    testObj.someMethod();

Live Demo