jQuery找不到元素

jQuery找不到元素

问题描述:

jQuery找不到任何元素. alert($("#testbutton").length);每次显示0.

jQuery is not finding any elements. alert($("#testbutton").length); displays 0 every time.

我做错什么了吗?

我的JS/jQuery代码:

(function ($) {
    alert($("#testbutton").length);
}) (jQuery);

我的HTML:

<html>
    <body>
        <div id="header">
            <div class="button" id="testbutton">Test</div>
        </div>
    </body>    
</html>

代码运行时,DOM未准备好,因此该元素不存在.您是不是要这样做(将函数传递给jQuery是$(document).ready(fn)的快捷方式):

When your code runs the DOM is not ready so the element doesn't exist. Did you mean to do this instead (passing a function to jQuery is a shortcut for $(document).ready(fn)):

$(function () {
    alert($("#testbutton").length);
});