jquery源码-jquery变量定义

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源码 15~93行，jquery变量定义

var
	// A central reference to the root jQuery(document)
	rootjQuery,//定义jquery根节点

	// The deferred used on DOM ready
	readyList,//Deferred 的存储用到

	// Use the correct document accordingly with window argument (sandbox)
    //下面的几段都是把JS本身的对象和方法做了本地的定义，这么做能减少每次调用全局的对象/方法,把当做juquery域内对象或方法，能提升性能，这是框架常用的写法
	document = window.document,
	location = window.location,
	navigator = window.navigator,

	// Map over jQuery in case of overwrite
	_jQuery = window.jQuery,

	// Map over the $ in case of overwrite
	_$ = window.$,

	// Save a reference to some core methods
	core_push = Array.prototype.push,
	core_slice = Array.prototype.slice,
	core_indexOf = Array.prototype.indexOf,
	core_toString = Object.prototype.toString,
	core_hasOwn = Object.prototype.hasOwnProperty,
	core_trim = String.prototype.trim,

	// Define a local copy of jQuery(定义一份本地的jquery的拷贝)
	jQuery = function( selector, context ) {
		// The jQuery object is actually just the init constructor 'enhanced'
		return new jQuery.fn.init( selector, context, rootjQuery );
	},

	// Used for matching numbers(匹配各类型的数字表示法)正/负/整型/浮点/科学计数法
	core_pnum = /[\-+]?(?:\d*\.|)\d+(?:[eE][\-+]?\d+|)/.source,

	// Used for detecting and trimming whitespace
	core_rnotwhite = /\S/,//匹配非空白字符
	core_rspace = /\s+/,//匹配多个空白字符

	// Make sure we trim BOM and NBSP (here's looking at you, Safari 5.0 and IE)
	rtrim = /^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g,

	// A simple way to check for HTML strings
	// Prioritize #id over  to avoid XSS via location.hash (#9521)
     //匹配含html标签字符串或#id形式的字符串
	rquickExpr = /^(?:[^#<]*(<[\w\W]+>)[^>]*$|#([\w\-]*)$)/,

	// Match a standalone tag (匹配标签符) 如  或 

	rsingleTag = /^<(\w+)\s*\/?>(?:<\/\1>|)$/,

	// JSON RegExp
	rvalidchars = /^[\],:{}\s]*$/,//匹配JSON字符串所包含的有效字符
	rvalidbraces = /(?:^|:|,)(?:\s*\[)+/g,
	rvalidescape = /\\(?:["\\\/bfnrt]|u[\da-fA-F]{4})/g,//匹配回车换行换页制表符或中文字符
	rvalidtokens = /"[^"\\\r\n]*"|true|false|null|-?(?:\d\d*\.|)\d+(?:[eE][\-+]?\d+|)/g,//匹配非回车换行的字符串/bool/null/数值

	// Matches dashed string for camelizing
	rmsPrefix = /^-ms-/,
	rdashAlpha = /-([\da-z])/gi,

	// Used by jQuery.camelCase as callback to replace()
    //转换为大写，这里有个疑问是为什么加了一个不需要的参数all？
	fcamelCase = function( all, letter ) {
		return ( letter + "" ).toUpperCase();
	},

	// The ready event handler and self cleanup method
    //定义浏览器docuemnt的加载完成事件快捷方式
	DOMContentLoaded = function() {
		if ( document.addEventListener ) {
			document.removeEventListener( "DOMContentLoaded", DOMContentLoaded, false );
			jQuery.ready();
		} else if ( document.readyState === "complete" ) {
			// we're here because readyState === "complete" in oldIE
			// which is good enough for us to call the dom ready!
			document.detachEvent( "onreadystatechange", DOMContentLoaded );
			jQuery.ready();
		}
	},

	// [[Class]] -> type pairs
	class2type = {};