javascript - 创建一个类，从另一个扩展并调用父方法

Question

首先，我从 coffeescript 站点获取了动物示例。

我想在 javascript 中模拟接下来的事情:

• 类(class)
• 仅限公共(public)方法
• 仅限私有(private)方法和变量
• 继承
• 从父类(super class)中调用方法

我认为这种创建方式是可以的，但是当我尝试从父类中获取move 方法时，它总是返回到自身。我做错了什么？

顺便说一句。哪些是实现我的目标的最佳实践？我的做法对吗？

var Animal = (function() {
    function Animal() {}

    var _private = {};
    var _public = {
        move: function() {
            console.log('Can move');
        }
    };

    Animal.prototype = _public;
    Animal.prototype.constructor = Animal;
    return Animal;
})();

var Snake = (function(_super) {
    function Snake() {}

    var _private = {};
    var _public = {
        move: function() {
            console.log(Snake._super_.move);
            console.log('Slithering');
        }
    };

    Snake.prototype = _super.prototype;
    Snake._super_ = _super.prototype;
    for(var method in _public) {
        if(Object.prototype.toString.call(_public[method]) === '[object Function]') {
            Snake.prototype[method] = _public[method];
        }
    }
    return Snake;
})(Animal);

var s = new Snake;
s.move();

Answer 1

在我看来，这段代码写得非常好，只有一个小错误。

我觉得你的指点有点不对，试试这个:

<script>
var Animal = (function () {
    function Animal() { }

    var _private = {};
    var _public = {
        move: function () {
            console.log('Can move');
            //this just returns a string to show which method was called
            //inside of the child's move function's console.log
            return "super move called";
        }
    };

    Animal.prototype = _public;
    Animal.prototype.constructor = Animal;
    return Animal;
})();

var Snake = (function (_super) {
    function Snake() { }

    var _private = {};
    var _public = {
        move: function () {
            console.log(Snake._super_.move());//Now we can call super's move
            console.log('Slithering');
        }
    };

    //This created the circular reference where Snake._super_ was pointing to
    //Snake.prototype which was causing the error
    //Snake.prototype = _super.prototype;
    Snake._super_ = _super.prototype;

    for (var method in _public) {
        if (Object.prototype.toString.call(_public[method]) === '[object Function]') {
            Snake.prototype[method] = _public[method];
        }
    }
    return Snake;
})(Animal);

var s = new Snake;
s.move();//now this outputs "Can move", "super move called", "Slithering"
</script>