Extension Function (1): Extend

The basic stone for writing good code is oo, and the most important feature for oo is implment.

This is why I choose write about implement as my first tech article.

No more to say.Just share my core code

Function.prototype.Implement = function (parentType) {
    //check parent is exists and parent's type is able to implment
    if (parentType != undefined && typeof (parentType) == "function") {
        var temp = this.prototype;
        this.prototype = new parentType();
        for (var i in temp) {
            this.prototype[i] = temp[i];
        }
        this.prototype.base = parentType.prototype;
    }
}

There is the core code.

Then we test the origin feature about extend in js.

First we declare parent class

var parent= function () {
    //constructor
}
parent.prototype = (function () {
    //private
    return {
        //public
        SomeVar:"I'm the first generation"
        DoSomeStaff:function(){
           console.write(this.SomeVar);
        }
    };
})();

Recommand this way to declare class.

as my comment in the code,there is a constructor, allow you write private method and public method.

But still can't declare private var.

After we declare parent then we declare child and extends from parent

var child= function () {
    //constructor
}
child.prototype = (function () {
    //private
    return {
        SomeVar:"I'm the second generation"
        DoSomeStaff:function(){
           this.base.DoSomeStaff.call(this);//call parent's method
        }
    };
})();
//child extend from parent
child.Implement(parent)

Declare done. then we test.

var p1=new parent();
p1.DoSomeStaff()//output:I'm the first generation
var c1=new child();
c1.DoSomeStaff()//output:I'm the second generation
c1 instanceof parent//true
c1 instanceof child//true

You can see, this way to written is more fit high-level language's grammar and make your code more readable.

But still this way to written extend still can't multi extend.

the last parent will replace all previous parent.