自己写的一个javascript map类

时间:2012-12-29 08:41来源:未知作者:admin 点击: 次

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在javascript中是没有Map类的，下面我自己封装一个js map类，分享现来给各位朋友参考。众所周之，js是没有Map类的，要想用还得自己封装一个。代码如下 (function(win) { var Map = function() {

在javascript中是没有Map类的，下面我自己封装一个js map类，分享现来给各位朋友参考。

众所周之，js是没有Map类的，要想用还得自己封装一个。

代码如下

(function(win) {
    var Map = function() {
        this.count = 0;
        this.entrySet = {};
    };

var proto = Map.prototype;

    proto.size = function() {
        return this.count;
    };

    proto.isEmpty = function() {
        return this.count === 0;
    };

    proto.containsKey = function(key) {
        if (this.isEmpty()) {
            return false;
        }

        for ( var prop in this.entrySet) {
            if (prop === key) {
                return true;
            }
        }

return false;
};

    proto.containsValue = function(value) {
        if (this.isEmpty()) {
            return false;
        }

        for ( var key in this.entrySet) {
            if (this.entrySet[key] === value) {
                return true;
            }
        }

return false;
};

    proto.get = function(key) {
        if (this.isEmpty()) {
            return null;
        }

        if (this.containsKey(key)) {
            return this.entrySet[key];
        }

return null;
};

    proto.put = function(key, value) {
        this.entrySet[key] = value;
        this.count++;
    };

    proto.remove = function(key) {
        if (this.containsKey(key)) {
            delete this.entrySet[key];
            this.count--;
        }
    };

    proto.putAll = function(map) {
        for ( var key in map.entrySet) {
            this.put(key, map.entrySet[key]);
        }
    };

    proto.clear = function() {
        for ( var key in this.entrySet) {
            this.remove(key);
        }
    };

proto.values = function() {
var result = [];

        for ( var key in this.entrySet) {
            result.push(this.entrySet[key]);
        }

return result;
};

proto.keySet = function() {
var result = [];

        for ( var key in this.entrySet) {
            result.push(key);
        }

return result;
};

    proto.toString = function() {
        var result = [];
        for ( var key in this.entrySet) {
            result.push(key + ":" + this.entrySet[key]);
        }

return "{" + result.join() + "}";
};

    proto.valueOf = function() {
        return this.toString();
    };

win.Map = Map;
})(window);