同事写的javascript hashMap

//实现hasnArrayMap
    var hashMap = function(){
        this.items = [];
        this.map = {};
    }
 
    hashMap.prototype.set =  function(key,value){
        var isFindInArray = false ;
        var obj ={key:key, value:value};
        for(var i = 0;i<this.items.length;i++){
            if(this.items[i].key == key) {
                obj.index = i;
                this.items[i] = obj;
                isFindInArray = true;
                break;
            }
        }
        if(!isFindInArray) {
            this.items.push(obj);
            obj.index = this.items.length - 1;
        }
        this.map[key] = value;
    }
 
    hashMap.prototype.get =  function(){
        var isKey = typeof(arguments[0]) === 'string';
        if(isKey) {
            return this.map[arguments[0]];
        } else {
            if(typeof(arguments[0])=='number') {
                var index = parseInt(arguments[0]);
                if(index >= 0 && index < this.items.length) {
                    return this.items[index].value;
                } else {
                    return 'undefined';
                }
            } else {
                return 'undefined';
            }
        }
    }
 
    hashMap.prototype.remove = function(){
        var isKey = typeof(arguments[0]) === 'string';
        if(isKey) {
            return this._remove(this.map[arguments[0]]);
        } else {
            if(typeof(arguments[0])=='number') {
                var index = parseInt(arguments[0]);
                if(index >= 0 && index < this.items.length) {
                    return this._remove(this.items[index]);
                } else {
                    return 'array over flow';
                }
            } else {
                return 'wrong arguments';
            }
        }
    }
 
    hashMap.prototype._remove = function(obj){
        if(obj) {
            var index = obj.index,
                key = obj.key;
            this.items.splice(index ,1);
            if(this.map[key])
                delete this.map[key];
        }
        return true;
    }
 
    hashMap.prototype.size = function(){
        return this.items.length;
    }
 
    /*
    var testArray = new SixDegree.hashMap();
    testArray.set('name1' , '1');
    testArray.set('name2' , '2');
    testArray.set('name3' , '3');
 
    console.log(testArray.get('name1'));
    console.log(testArray.get('name2'));
    console.log(testArray.get('name3'));
 
    console.log(testArray.get(0));
    console.log(testArray.get(1));
    console.log(testArray.get(2));
 
    testArray.remove(0);
 
    for(var i=0 , len = testArray.size();i<len ; i++){
        console.log(testArray.get(i));
    }
 
    testArray.remove('name2');
    for(var i=0 , len = testArray.size();i<len ; i++){
        console.log(testArray.get(i));
    }
    */
 