Map Utility for JavaScript

JavaScript-Map.js

/**
 * Created by lica on 6/12/2016.
 */
function Map() {
    this.container = new Object();
}

Map.prototype.put = function (key, value) {
    this.container[key] = value;
}

Map.prototype.get = function (key) {
    return this.container[key];
}

Map.prototype.putAll = function (map) {
    for (var key in map.container) {
        if (key == 'extend') {
            continue;
        }
        this.container[key] = map.container[key];
    }
}

Map.prototype.entrySet = function () {
    var set = new Array();

    function Entry() {
        this.entry = new Object();
    }

    Entry.prototype.getKey = function () {
        for (var key in this.entry) {
            if (key == 'extend') {
                continue;
            }
            return key;
        }
    }

    Entry.prototype.getValue = function () {
        for (var key in this.entry) {
            if (key == 'extend') {
                continue;
            }
            return this.entry[key];
        }
    }

    for (var key in this.container) {
        var entry = new Entry();
        if (key == 'extend') {
            continue;
        }
        entry.entry[key] = this.container[key];
        set.push(entry);
    }
    return set;
}

Map.prototype.keySet = function () {
    var keySet = new Array();
    var count = 0;
    for (var key in this.container) {
        // skip object's extend function
        if (key == 'extend') {
            continue;
        }
        keySet[count] = key;
        count++;
    }
    return keySet;
}

Map.prototype.values = function () {
    var values = new Array();
    for (var key in this.container) {
        if (key == 'extend') {
            continue;
        }
        values.push(this.container[key]);
    }
    return values;
}

Map.prototype.isEmpty = function () {
    var flag = true;
    for (var key in this.container) {
        if (key == 'extend') {
            continue;
        }
        flag = false;
        break;
    }
    return flag;
}

Map.prototype.size = function () {
    var count = 0;
    for (var key in this.container) {
        // skip object's extend function
        if (key == 'extend') {
            continue;
        }
        count++;
    }
    return count;
}

Map.prototype.remove = function (key) {
    delete this.container[key];
}

Map.prototype.clear = function () {
    for (var key in this.container) {
        if (key == 'extend') {
            continue;
        }
        delete this.container[key];
    }
}

Map.prototype.clone = function () {
    var cloneObj = new Map();
    cloneObj.putAll(this);
    return cloneObj;
}

Map.prototype.toString = function () {
    var str = "";
    for (var i = 0, keys = this.keySet(), len = keys.length; i < len; i++) {
        str = str + keys[i] + "=" + this.container[keys[i]] + ";\n";
    }
    return str;
}