javascript的一个map实现

很早收集的，不知道是从哪里流传出来，整理下分享给大家

function Map() {

	// 底层保存数据结构
	var struct = function(key, value) {
		this.key = key;
		this.value = value;
	};

	// 如果key相同值会被覆盖
	var put = function(key, value) {
		for ( var i = 0; i < this.size(); i++) {
			if (this.arr[i].key === key) {
				this.arr[i].value = value;
				return;
			}
		}

		this.arr[this.arr.length] = new struct(key, value);
	};

	// 根据key获取值
	var get = function(key) {
		for ( var i = 0; i < this.size(); i++) {
			if (this.arr[i].key === key) {
				return this.arr[i].value;
			}
		}

		return null;
	};

	// 删除
	var remove = function(key) {
		for ( var i = 0; i < this.size(); i++) {
			if (this.arr[i].key === key) {
				this.arr.splice(i, 1);
			}
		}
	};

	var size = function() {
		return this.arr.length;
	};

	var isEmpty = function() {
		return this.size() <= 0;
	};

	// 迭代所有key
	var listKeys = function() {
		var key = [];
		for ( var i = 0; i < this.size(); i++) {
			key.push(this.arr[i].key);
		}
		return key;
	};

	var methodParamNames = function(method) {
		var names = new Array;
		for ( var i = 0; i < this.size(); i++) {
			if (this.arr[i].key.indexOf(method + '_') >= 0) {
				var vals = this.arr[i].key.split("_");
				if (vals[2] != "result")
					names.push(vals[1]);
			}
		}

		return names;
	};

	// 暴露私有方法
	this.arr = new Array();
	this.get = get;
	this.put = put;
	this.remove = remove;
	this.size = size;
	this.isEmpty = isEmpty;
	this.methodParamNames = methodParamNames;
	this.keys = listKeys;
}

 

简单的测试：

var map = new Map();
map.put("name", "robin");
map.put("1", "aaaa");
map.put(1, "bbbb");
console.log(map.arr);
console.log(map.size());
console.log(map.keys());
console.log(map.get("1"));
map.remove(1);
console.log(map.size());