锋利的jQuery学习笔记-write less do more-选择器中空格的示例

<div class=test>
    <div style = display:none>aa</div>
    <div style = display:none>bb</div>
    <div style = display:none>cc</div>
    <div class = test style = display:none>dd</div>
</div>
<div class = test style =display:none>ee</div>
<div class=test style = display:none>ff</div>
$(document).ready(function(){
    var $hide = $(".test :hidden");
    var $hide2 = $(".test:hidden");
    alert($hide.length);//4 
    alert($hide2.length);//3
});

解析:
空格 :代表后代选择器
(.test:hidden)class=testdivhidden(“.test:hidden”) 获取的是所有class=test并且属性为hidden的元素

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