JS implements JAVA's List function

function List(){
    var list = new Array();
    /* 添加元素 */
    this.add = function(obj){
        list[list.length] = obj;
    }
    /* 根据下标获得元素 */
    this.get = function(index){
        return list[index];
    }
    /* 根据下标移除元素 */
    this.remove = function(index){
        var obj = list[index];
        list.splice(index, 1);
        return obj;
    }
    /* 清空对象中元素 */
    this.clear = function(){
        list.splice(0, list.length);
    }
    /* 对象元素大小 */
    this.size = function(){
        return list.length;
    }
}