Re: [ js ] 幾種 define class 的 patterns

[TonyQ (沉默是金。)]

※ 引述《B9 (葉酸酸)》之銘言：
:  1. 定義 function 再把 method 加到 prototype 裡面。
: function Cat(){}
: Cat.prototype.eat = function(){};
: Cat.prototype.drink = function(){};
: constructor 當然可以像下面這樣寫。
: var Cat = function(){};
: 不過我個人喜歡下面這樣寫，因為比較像傳統 OOP 定義 class 的方法：
: function Cat()
: {
:     arguments.callee.prototype.eat = function(){};
:     arguments.callee.prototype.drink = function(){};
: }

        It's not good , every time you new a instance ,
        it need to re-allocate again , and you couldn't overwrite it anyway.

        Because every time you new a object,
        the prototype is writing again.

        (you might not need it , but it's still bad for performance.)


: > -------------------------------------------------------------------------- <
:  2. 與第一型一樣定義 function，但重新定義 prototype object。
: function Cat(){}
: Cat.prototype =
: {
:     eat: function(){},
:     drink: function(){}
: }

        I prefer this one , it's nature and effective.

: > -------------------------------------------------------------------------- <
:  3. 在 Function 的 prototype object 中新增一個宣告 method 的 function，
:     再利用這個 function 宣告 methods。
: Function.prototype.method = function(name, fn){ this.prototype[name] = fn; };
: function Cat(){}
: Cat.method("eat", function(){});
: Cat.method("drink", function(){});

        Not native enough...
        but it's good to do some overwrite job or method fn queue if need.


: > -------------------------------------------------------------------------- <
:  4. 與第三型相似，但透過小小改寫，變成 chaining pattern。
: Function.prototype.method = function(name, fn){
:     this.prototype[name] = fn;
:     return this;
: };
: Cat.method("eat", function(){}).method("drink", function(){});


: > -------------------------------------------------------------------------- <
:  5. 如果你的 class 只有一個物件的話，可以考慮 singleton。
: var Cat =
: {
:     eat: function(){},
:     drink: function(){}
: };
: > -------------------------------------------------------------------------- <
: 這是 JavaScript 的美。:D


        If you are talking about all the approach,
        there's another way for not to use prototype ,

        like

        function Cat(){
                this.eat = function(){};
                this.drink = function(){};
        }


        var c1 = new Cat();
        var c2 = new Cat();
        (it's still bad for performance, and not extendable after it created.)

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◆ From: 198.203.175.175
※ 編輯: TonyQ           來自: 198.203.175.175      (03/23 03:16)
推 linhomeyeu:tony大的中文輸入掛點了嗎XD
→ TonyQ:我在美國出差，有時沒中文輸入法可以用XD
推 B9:Thank you really much. :)
推 gpmm:prefer XDDD
※ 編輯: TonyQ           來自: 198.203.175.175      (03/23 22:17)
※ 編輯: TonyQ           來自: 198.203.175.175      (03/23 22:18)