有人可以向我解释继承如何在javascript中工作

Question

can somebody please explain me How Inheritance works in javascript (JS), i have gone through many Tutorials, but I'm not able to understand what it is achieving.. even after night and day no result..

what i have gone through is :

console.log('Initialized..')

function Animal() {
    this.species = "animal";
}

Animal.prototype.category = function (){
    alert(this.species);
}

function Dog(){
    this.Animal();
}

copyPrototype(Dog, Animal)
var d = new Dog();
d.category();

Referenced Tutorial from http://www.sitepoint.com/javascript-inheritance/

Answer 1

In my opinion this: http://www.letscodejavascript.com/v3/episodes/lessons_learned/12 is the best resource on understanding the mechanics we abuse when trying to get classical OOP working in JavaScript.

The following is what I do when someone tells me I must use OOP in JS. It's probably something I've picked up online somewhere. Anyways, here goes:

/// Make this script available somewhere
var extendsClass = this.extendsClass || function (d, b) {
    function __inheritedProto() { this.constructor = d; }
    __inheritedProto.prototype = b.prototype;
    d.prototype = new __inheritedProto();
}

var Animal = (function() {
    function Animal(data) {
        this.value = data;
    }
    Animal.prototype.method = function() {
        return this.value;
    };
    return Animal;
})();

var Dog = (function(_super) {
    extendsClass(Dog, _super);
    function Dog() {
        _super.apply(this, arguments);
    }
    Dog.prototype.method2 = function() {
        return this.value * 2; //do something else
    };
    return Dog;
})(Animal);

/// Create some instances
var animal = new Animal(1);
var dog = new Dog(2);


/// Call some methods
animal.method();  // 1
dog.method(); // 2
dog.method2();// 4