本文实例讲述了JS模拟的Map类。分享给大家供大家参考，具体如下：
根据java中map的属性，实现key----value保存
1、使用数组方式存储数据，（使用闭包）
function Map() {
var struct = function (key, value) {
this.key = key;
this.value = value;
}
var put = function (key, value) {
for (var i = 0; i < this.arr.length; i++) {
if (this.arr[i].key === key) {
this.arr[i].value = value;
return;
}
}
this.arr[this.arr.length] = new struct(key, value);
}
var get = function (key) {
for (var i = 0; i < this.arr.length; i++) {
if (this.arr[i].key === key) {
return this.arr[i].value;
}
}
return null;
}
var remove = function (key) {
var v;
for (var i = 0; i < this.arr.length; i++) {
v = this.arr.pop();
if (v.key === key) {
continue;
}
this.arr.unshift(v);
}
}
var size = function () {
return this.arr.length;
}
var isEmpty = function () {
return this.arr.length <= 0;
}
this.arr = new Array();
this.get = get;
this.put = put;
this.remove = remove;
this.size = size;
this.isEmpty = isEmpty;
}
2、使用JSON方式存储数据（使用原型方式拓展方法）
function Map() {
this.obj = {};
this.count = 0;
}
Map.prototype.put = function (key, value) {
var oldValue = this.obj[key];
if (oldValue == undefined) {
this.count++;
}
this.obj[key] = value;
}
Map.prototype.get = function (key) {
return this.obj[key];
}
Map.prototype.remove = function (key) {
var oldValue = this.obj[key];
if (oldValue != undefined) {
this.count--;
delete this.obj[key];
}
}
Map.prototype.size = function () {
return this.count;
}
var map = new Map();
map.put("key","map");
map.put("key","map1");
alert(map.get("key"));//map1
map.remove("key");
alert(map.get("key"));//undefined
希望本文所述对大家JavaScript程序设计有所帮助。
