Javascript上实现MAP

Javascript下实现MAP

* Make a map like java.
* You can use this map like this :
* var myMap = new Map();
* myMap.put("key","value");
* var key = myMap.get("key");
*/
function Map() {   

    this.elements = new Array();   

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

    this.isEmpty = function() {
        return (this.elements.length < 1);
    }   

    this.clear = function() {
        this.elements = new Array();
    }   

    this.put = function(_key, _value) {
        this.elements.push({key:_key, value:_value});
    }   

    this.remove = function(_key) {
        var bln = false;   

        try {
            for (i = 0; i < this.elements.length; i++) {
                if (this.elements[i].key == _key) {
                    this.elements.splice(i, 1);
                    return true;
                }
            }
        } catch(e) {
            bln = false;
        }
        return bln;
    }   

    this.get = function(_key) {
        try{
            for (i = 0; i < this.elements.length; i++) {
                if (this.elements[i].key == _key) {
                    return this.elements[i].value;
                }
            }
        }catch(e) {
            return null;
        }
    }   

    this.element = function(_index) {
        if (_index < 0 || _index >= this.elements.length) {
            return null;
        }
        return this.elements[_index];
    }   

    this.containsKey = function(_key) {
        var bln = false;
        try {
            for (i = 0; i < this.elements.length; i++) {
                if (this.elements[i].key == _key) {
                    bln = true;
                }
            }
        }catch(e) {
            bln = false;
        }
        return bln;
    }   

    this.containsValue = function(_value) {
        var bln = false;
        try {
            for (i = 0; i < this.elements.length; i++) {
                if (this.elements[i].value == _value){
                    bln = true;
                }
            }
        } catch(e) {
            bln = false;
        }
        return bln;
    }   

    this.values = function() {
        var arr = new Array();
        for (i = 0; i < this.elements.length; i++) {
            arr.push(this.elements[i].value);
        }
        return arr;
    }   

    this.keys = function() {
        var arr = new Array();
        for (i = 0; i < this.elements.length; i++) {
            arr.push(this.elements[i].key);
        }
        return arr;
    }
}