在JavaScript中计算嵌套的div

Question

嘿我需要用给定的类名来计算嵌套的div.例如:

<div id = "divA">
    <div class = "anotherName"></div>
    <div class = "toBeCounted"></div>
    <div class = "someName"></div>
    <div class = "toBeCounted"></div>
    <div class = "toBeCounted"></div>
    <div class = ""></div>
</div>
<div id = "divB">
    <div class = ""></div>
    <div class = "toBeCounted"></div>
    <div class = ""></div>
    <div class = "toBeCounted"></div>
</div>

因此,如果我想计算"toBeCounted",我将获得3为divA和2为divB.

Answer 1

您可以使用.querySelectorAll()并检查结果的长度:

var divAcount = document.querySelectorAll("#divA > .toBeCounted").length;

这种>关系坚持认为.toBeCounted元素是直接的孩子divA.如果那不是你想要的,而且任何 toBeCounted内部的div divA应该算在内,那你就省略了>.