$.type()，js数据类型判断

class2type = {}

core_toString = class2type.toString

jQuery.each("Boolean Number String Function Array Date RegExp Object Error".split(" "), function(i, name) {class2type[ "[object " + name + "]" ] = name.toLowerCase();});

jQuery.type = function( obj ) {

if ( obj == null ) { return String( obj ); } // Support: Safari <= 5.1 (functionish RegExp) return typeof obj === "object" || typeof obj === "function" ? class2type[ core_toString.call(obj) ] || "object" : typeof obj;},