继承的4种基本方式

        function Parent(){
            this.name = "Parent";
        }
        function Child(){
            Parent.call(this);
        }
        var child = new Child();
        console.log(child.name);   

        function Parent(){
            this.name = "Parent";
        }
        function Child(){
        }
        Child.prototype = new Parent();
        var child = new Child();
        console.log(child.name);

function ArrayCollection(){
    return [];
}

var ac = new ArrayCollection();