jQuery中的类型判断

 1 var class2type = {};
 2 var toString = class2type.toString;
 3 jQuery.each("Boolean Number String Function Array Date RegExp Object Error".split(" "), function(i, name) {
 4     class2type[ "[object " + name + "]" ] = name.toLowerCase();
 5 });
 6 type: function( obj ) {
 7     if ( obj == null ) {
 8         return obj + "";
 9     }
10     return typeof obj === "object" || typeof obj === "function" ?
11         class2type[ toString.call(obj) ] || "object" :
12         typeof obj;
13 }

1 isFunction: function( obj ) {
2     return jQuery.type(obj) === "function";
3 },
4 
5 isArray: Array.isArray || function( obj ) {
6     return jQuery.type(obj) === "array";
7 },

1 isWindow: function( obj ) {
2     return obj != null && obj == obj.window;
3 },

 1 isPlainObject: function( obj ) {
 2         // Not plain objects:
 3         // - Any object or value whose internal [[Class]] property is not "[object Object]"
 4         // - DOM nodes
 5         // - window
 6         if ( jQuery.type( obj ) !== "object" || obj.nodeType || jQuery.isWindow( obj ) ) {
 7             return false;
 8         }
 9 
10         // Support: Firefox <20
11         // The try/catch suppresses exceptions thrown when attempting to access
12         // the "constructor" property of certain host objects, ie. |window.location|
13         // https://bugzilla.mozilla.org/show_bug.cgi?id=814622
14         try {
15             if ( obj.constructor &&
16                     !core_hasOwn.call( obj.constructor.prototype, "isPrototypeOf" ) ) {
17                 return false;
18             }
19         } catch ( e ) {
20             return false;
21         }
22 
23         // If the function hasn‘t returned already, we‘re confident that
24         // |obj| is a plain object, created by {} or constructed with new Object
25         return true;
26     }

1 isEmptyObject: function( obj ) {
2     var name;
3     for ( name in obj ) {
4         return false;
5     }
6     return true;
7 }

//1.11.2
isNumeric: function( obj ) {
    return !jQuery.isArray( obj ) && (obj - parseFloat( obj ) + 1) >= 0;
},