js实现map功能

var Map = function() {this.mapArr = {};this.arrlength = 0;//假如有重复key，则不存入  this.put = function(key, value) {if (!this.containsKey(key)) {this.mapArr[key] = value;this.arrlength = this.arrlength + 1;}}this.get = function(key) {return this.mapArr[key];}//传入的参数必须为Map结构  this.putAll = function(map) {if (Map.isMap(map)) {var innermap = this;map.each(function(key, value) {innermap.put(key, value);})} else {alert("传入的非Map结构");}}this.remove = function(key) {delete this.mapArr[key];this.arrlength = this.arrlength - 1;}this.size = function() {return this.arrlength;}//判断是否包含key  this.containsKey = function(key) {return (key in this.mapArr);}//判断是否包含value  this.containsValue = function(value) {for ( var p in this.mapArr) {if (this.mapArr[p] == value) {return true;}}return false;}//得到所有key 返回数组  this.keys = function() {var keysArr = [];for ( var p in this.mapArr) {keysArr[keysArr.length] = p;}return keysArr;}//得到所有value 返回数组  this.values = function() {var valuesArr = [];for ( var p in this.mapArr) {valuesArr[valuesArr.length] = this.mapArr[p];}return valuesArr;}this.isEmpty = function() {if (this.size() == 0) {return false;}return true;}this.clear = function() {this.mapArr = {};this.arrlength = 0;}//循环  this.each = function(callback) {for ( var p in this.mapArr) {callback(p, this.mapArr[p]);}}}//判断是否是map对象  Map.isMap = function(map) {return (map instanceof Map);}