在 jQuery 插件中传递参数是什么意思？

Question

我见过很多插件，其中包括文档、窗口、未定义等对象到打开和关闭的参数中。

这有必要吗？ 这是什么意思？ 什么时候应该使用这些？

;(function( $ , document, window, undefined) {
        "use strict";        

      $.fn.pluginname= function(options) {      

        //Code

      };
    })( jQuery, document, window, undefined);

Answer 1

来自jqueryboilerplate.com

 // undefined is used here as the undefined global variable in ECMAScript 3 is
 // mutable (ie. it can be changed by someone else). undefined isn't really being
 // passed in so we can ensure the value of it is truly undefined. In ES5, undefined
 // can no longer be modified.

 // window and document are passed through as local variable rather than global
 // as this (slightly) quickens the resolution process and can be more efficiently
 // minified (especially when both are regularly referenced in your plugin).

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另外，你的例子有点不正确：你不应该在调用函数时在最后一行传入'undefined'。我在上面粘贴的第一段中解释了原因。