JavaScript中实现Map的示例代码
JavaScript中实现Map的示例代码
发布时间:2016-12-30 来源:查字典编辑
摘要:不废话了,直接贴代码了。代码一:varmap=newMap();map.put("a","A");map.put("b","B");map....

不废话了,直接贴代码了。

代码一:

var map=new Map(); map.put("a","A");map.put("b","B");map.put("c","C"); map.get("a"); //返回:A map.entrySet() // 返回Entity[{key,value},{key,value}] map.containsKey('kevin') //返回:false

function Map() { this.keys = new Array(); this.data = new Object(); /** * 放入一个键值对 * @param {String} key * @param {Object} value */ this.put = function(key, value) { if(this.data[key] == null){ this.keys.push(key); this.data[key] = value; }else{ this.data[key]=this.data[key]; } return true; }; /** * 获取某键对应的值 * @param {String} key * @return {Object} value */ this.get = function(key) { return this.data[key]; }; /** * 删除一个键值对 * @param {String} key */ this.remove = function(key) { for(var i=0;i<this.keys.length;i++){ if(key===this.keys[i]){ var del_keys= this.keys.splice(i,1); for(k in del_keys){ this.data[k] = null; } return true; } } return false; }; /** * 遍历Map,执行处理函数 * * @param {Function} 回调函数 function(key,value,index){..} */ this.each = function(fn){ if(typeof fn != 'function'){ return; } var len = this.keys.length; for(var i=0;i<len;i++){ var k = this.keys[i]; fn(k,this.data[k],i); } }; /** * 获取键值数组 * @return entity[{key,value},{key,value}] */ this.entrySet = function() { var len = this.keys.length; var entrys = new Array(len); for (var i = 0; i < len; i++) { entrys[i] = { key : this.keys[i], value : this.data[this.keys[i]] }; } return entrys; }; /** * 判断Map是否为空 */ this.isEmpty = function() { return this.keys.length == 0; }; /** * 获取键值对数量 */ this.size = function(){ return this.keys.length; }; this.containsKey=function(key){ return this.keys.filter(function(v){ if(v===key){ return key; } }).length>0; }; /** * 重写toString */ this.toString = function(){ var s = "{"; for(var i=0;i<this.keys.length;i++){ var k = this.keys[i]; s += k+"="+this.data[k]; if(this.keys.length>i+1){ s+=',' } } s+="}"; return s; }; /** * 解析字符串到Map * {a=A,b=B,c=B,} */ this.parserStringAndAddMap=function(str){ var count=0; if(str && str.length>0){ str=str.trim(); var startIndex=str.indexOf("{"),endIndex=str.lastIndexOf("}"); if(startIndex!==-1 && endIndex!==-1){ str=str.substring(startIndex+1,endIndex); var arrs= str.split(","); for(var i=0;i<arrs.length;i++){ var kv=arrs[i].trim(); if(kv.length>0 && kv.indexOf("=")!==-1){ var kv_arr=kv.split("="); if(kv_arr.length==2){ if(this.put(kv_arr[0].trim(),kv_arr[1].trim())){ count++; }else{ console.error('error: kv:'+kv); } } } } }else{ console.log("data error:"+str); } }else{ console.log('data is not empty'); } return count; }; }

代码二:

Array.prototype.remove = function(s) { for (var i = 0; i < this.length; i++) { if (s == this[i]) this.splice(i, 1); } } /** * Simple Map * * * var m = new Map(); * m.put('key','value'); * ... * var s = ""; * m.each(function(key,value,index){ * s += index+":"+ key+"="+value+"n"; * }); * alert(s); * * @author dewitt * @date 2008-05-24 */ function Map() { /** 存放键的数组(遍历用到) */ this.keys = new Array(); /** 存放数据 */ this.data = new Object(); /** * 放入一个键值对 * @param {String} key * @param {Object} value */ this.put = function(key, value) { if(this.data[key] == null){ this.keys.push(key); } this.data[key] = value; }; /** * 获取某键对应的值 * @param {String} key * @return {Object} value */ this.get = function(key) { return this.data[key]; }; /** * 删除一个键值对 * @param {String} key */ this.remove = function(key) { this.keys.remove(key); this.data[key] = null; }; /** * 遍历Map,执行处理函数 * * @param {Function} 回调函数 function(key,value,index){..} */ this.each = function(fn){ if(typeof fn != 'function'){ return; } var len = this.keys.length; for(var i=0;i<len;i++){ var k = this.keys[i]; fn(k,this.data[k],i); } }; /** * 获取键值数组(类似Java的entrySet()) * @return 键值对象{key,value}的数组 */ this.entrys = function() { var len = this.keys.length; var entrys = new Array(len); for (var i = 0; i < len; i++) { entrys[i] = { key : this.keys[i], value : this.data[i] }; } return entrys; }; /** * 判断Map是否为空 */ this.isEmpty = function() { return this.keys.length == 0; }; /** * 获取键值对数量 */ this.size = function(){ return this.keys.length; }; /** * 重写toString */ this.toString = function(){ var s = "{"; for(var i=0;i<this.keys.length;i++,s+=','){ var k = this.keys[i]; s += k+"="+this.data[k]; } s+="}"; return s; }; }

function testMap(){ var m = new Map(); m.put('key1','Comtop'); m.put('key2','南方电网'); m.put('key3','景新花园'); alert("init:"+m); m.put('key1','康拓普'); alert("set key1:"+m); m.remove("key2"); alert("remove key2: "+m); var s =""; m.each(function(key,value,index){ s += index+":"+ key+"="+value+"n"; }); alert(s); }

以上内容通过两段代码给大家分享了JavaScript中实现Map,希望大家喜欢。

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