用js寫一個實現map
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<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>無標題文檔</title>
<script language="javascript">
Array.prototype.remove = function(s) {
for (var i = 0; i < this.length; i++) {
if (s == this[i])
this.splice(i, 1);
}
}
function Map() {
/** 存放鍵的數組(遍歷用到) */
this.keys = new Array();
/** 存放數據 */
this.data = new Object();
/**
* 放入一個鍵值對
* @param {String} key
* @param {Object} value
*/
this.put = function(key, value) {
if(this.data[key] == null){
this.keys.push(key);
}
this.data[key] = value;
};
/**
* 獲取某鍵對應的值
* @param {String} key
* @return {Object} value
*/
this.get = function(key) {
return this.data[key];
};
/**
* 刪除一個鍵值對
* @param {String} key
*/
this.remove = function(key) {
this.keys.remove(key);
this.data[key] = null;
};
/**
* 遍歷Map,執行處理函數
*
* @param {Function} 回調函數 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);
}
};
/**
* 獲取鍵值數組(類似Java的entrySet())
* @return 鍵值對象{key,value}的數組
*/
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;
};
/**
* 判斷Map是否爲空
*/
this.isEmpty = function() {
return this.keys.length == 0;
};
/**
* 獲取鍵值對數量
*/
this.size = function(){
return this.keys.length;
};
/**
* 重寫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','南方電網');
m.put('key3','景新花園');
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);
}
</script>
</head>
<body onload="testMap()">
</body>
</html>
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