JavaScript回调函数问题

Question

请参阅下面的代码：

        var callback = function(popup_window) {
            popup_window.close();
           //some more codes here
        };
        var prepare = function(cb) {
            popup_window = window.open("my_url");
            this.cb(popup_window);
        };
        function refresh(){
            prepare(callback);
        };

如何将 popup_window 变量传递给回调函数？

Answer 1

将this.cb(popup_window);更改为cb(popup_window);

Answer 2

 var prepare = function(cb) {
        var popup_window = window.open("my_url");
        cb(popup_window);
    };

Answer 3

将this.cb()替换为cb()