js List 对象封装【原创】

var List = function (arr) { 
 
            /// <summary> 
 
            /// 加载数组列表 
 
            /// </summary> 
 
            /// <returns type="List" /> 
 
            /// <param name="arr">数组</param> 
 
            return List.fn.Load(arr); 
 
        }; 
 
        List.fn = List.prototype = { 
 
            /// <summary> 
 
            /// 加载数组列表 
 
            /// </summary> 
 
            /// <returns type="List" /> 
 
            /// <param name="arr">数组</param> 
 
            Load: function (arr) { 
 
                this.length = 0; 
 
                Array.prototype.push.apply(this, arr); 
 
                return this; 
 
            }, 
 
            First: function (key, value) { 
 
                return this.Where(key, value)[0]; 
 
            }, 
 
            /*Where: function (key, value) { 
 
            var arr = []; 
 
            for (i = 0; i < this.length; i++) { 
 
            if (this[i][key] == value) 
 
            arr.push(this[i]); 
 
            } 
 
            return arr; 
 
            },*/ 
 
            Where: function (callback) { 
 
                var arr = []; 
 
                for (i = 0; i < this.length; i++) { 
 
                    if (callback.call(this[i],i,this[i])===true) 
 
                        arr.push(this[i]); 
 
                } 
 
                return arr; 
 
            }, 
 
            Select: function (key) { 
 
                var arr = []; 
 
                for (i = 0; i < this.length; i++) { 
 
                    arr.push(this[i][key]); 
 
                } 
 
                return arr; 
 
            } 
 
        };