欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  web前端

javascript全局变量封装模块实现代码_javascript技巧

程序员文章站 2022-03-27 10:49:33
...
下面的代码是我的测试代码,注释很重要:
复制代码 代码如下:

/*global window,jQuery,validate_email,masterUI,$,rest*/
/** Enable ECMAScript "strict" operation for this function. See more:
* http://ejohn.org/blog/ecmascript-5-strict-mode-json-and-more/
* http://*.com/questions/5020479/what-advantages-does-using-functionwindow-document-undefined-windo
* Q1: Why are window and document being fed instead of just being accessed normally?
* A1: Generally to fasten the identifier resolution process, having them as local variables can help (although IMO the performance improvements may be negligible).
* A2: Passing the global object is also a widely used technique on non-browser environments, where you don't have a window identifier at the global scope, e.g.:
* (function (global) {
* //..
* })(this); // this on the global execution context is the global object itself
* A3: Passing window and document allows the script to be more efficiently minified
*
* Q2: Why the heck is undefined being passed in?
* A1: This is made because the undefined global property in ECMAScript 3, is mutable, meaning that someone could change its value affecting your code, for example:
* undefined = true; // mutable
* (function (undefined) {
* alert(typeof undefined); // "undefined", the local identifier
* })(); // * If you look carefully undefined is actually not being passed (there's no argument on the function call),
* that's one of the reliable ways to get the undefined value, without using the property window.undefined.
*
*/
(function(window, document, undefined) {
"use strict";
window.test = {
init: function () {
"use strict";
alert("ok");
}
};
})(window, document);// no undefined parameter here to avoid using mutable window.undefined changed by other guy

1.说明,参考了一篇文章和*上的一个帖子
2.(function(){})() 这种代码写在独立的js文件里,当js文件被html加载的时候,该函数就会执行。实际上创建了windows.text对象。
以后html代码就可用test.init的形式调用方法。
测试html部分代码如下:
复制代码 代码如下:

[plain] view plaincopyprint?

AppEngine SDK








3.Jslint会报两个问题,一是关于undefined的,没找到什么好方法,任它抱怨吧。另一格式最后调用方式要改成:
复制代码 代码如下:

[javascript] view plaincopyprint?}(window, document)); }(window, document));

无所谓了,就任由它吧。只要功能正常就行。