JavaScript 获取对象类名的实现方法

var getObjectClass = function (obj) {
 if (obj && obj.constructor && obj.constructor.toString()) {
   /*
    * for browsers which have name property in the constructor
    * of the object,such as chrome 
    */
   if(obj.constructor.name) {
    return obj.constructor.name;
   }
   var str = obj.constructor.toString();
   /*
    * executed if the return of object.constructor.toString() is 
    * "[object objectClass]"
    */
   if(str.charAt(0) == '[')
   {
     var arr = str.match(/\[\w+\s*(\w+)\]/);
   } else {
     /*
      * executed if the return of object.constructor.toString() is 
      * "function objectClass () {}"
      * for IE Firefox
      */
     var arr = str.match(/function\s*(\w+)/);
   }
   if (arr && arr.length == 2) {
      return arr[1];
   }
  }
  return undefined; 
};