伪古典继承

Question

I am currently working through Javascript the good parts which is a amazingly good book but as the heading saying I seem to be hitting a dead end getting the code to work for chapter five. When I run the code I am getting nothing in return so I'm not sure where its wrong as its just like the book, any help is great.

Function.method('new',function(){
  var that  = Object.beget(this.prototype);
  var other = this.apply(that,arguments);

  return  (typeof other === 'object' && other) || that ;
});

var Mammal = function(name){
  this.name = name;
};

Mammal.prototype.get_name = function(){
  return this.name;
};

Mammal.prototype.says = function(){
  return this.saying || '';
}

var myMammal = new Mammal('Herb the mammal');

var name = myMammal.get_name();

document.writeln(name);

Answer 1

Please refer 'Augmenting Types' in Chapter 'Functions' of 'JavaScript - The Good Parts'.

Please add the following code prior to the code posted in the question.

This will make the method function available on Function .

Function.prototype.method = function (name, func) {
     this.prototype[name] = func;
     return this;
};

Please refer this fiddle for the complete working code.

Please note new method is already available on Function . The code displays how to augment .

You can get rid of the following blocks from your code.

Function.method('new',function(){
  var that  = Object.beget(this.prototype);
  var other = this.apply(that,arguments);

  return  (typeof other === 'object' && other) || that ;
});

But should you need to retain the above block , you have to augment method function to Function .