Question

var app = app || {};

(function ($) {
    app.initialize = {
        init: function () {
            app.initialize.fullScreen();
        },
        fullScreen: function () {
            var scrHeight = $window.height();
            console.log($fullScreenEl.length);
            $fullScreenEl.css('height', scrHeight);
        }
    };

    app.documentOnReady = {
        init: function () {
            app.initialize.init();
        }
    };


    var $window = $(window),
        $fullScreenEl = $('.full-screen');

    $(document).ready(app.documentOnReady.init);

})(jQuery);

这是我的代码，当我运行代码$ fullScreenEl长度返回零时，我不明白为什么。如果从（function（$）{}）（jQuery）移动Document就绪;然后$（'。全屏'）。lenght返回1.有人可以给我一些建议吗？

Answer 1

以这种方式改变：

(function ($) {
    app.initialize = {
        init: function () {
            app.initialize.fullScreen();
        },
        fullScreen: function () {

           var $window = $(window),
               $fullScreenEl = $('.full-screen');

            var scrHeight = $window.height();
            console.log($fullScreenEl.length);
            $fullScreenEl.css('height', scrHeight);
        }
    };

    app.documentOnReady = {
        init: function () {
            app.initialize.init();
        }
    };


    $(document).ready(app.documentOnReady.init);

})(jQuery);

您必须在文档准备好后选择元素。此外，通过移动$window函数内部的$fullScreenEl和fullScreen，性能更好，因为访问范围之外的变量比在同一范围内访问变量要慢。

Jquery选择器长度返回0

1 个答案: