选择最后3个子节点 [英] select the last 3 childs

问题描述

我知道你可以用：last-child 选择最后一个寒意。现在我需要选择最后3个孩子唯一的问题是孩子的数量是不知道所以我不能使用：nth-​​child ，我知道有一些东西叫做：nth-​​last-child 但我真的不能理解这是如何工作的

I know you can select the last chill with :last-child. now i need to select the last 3 childs the only problem is the amount of childs is not know so i cant use :nth-child, i know there is something that's called :nth-last-child but i cant really understand how this is working

<div id="something">

    <a href="images/x.jpg"  ><a/>
    <a href="images/x.jpg"  ><a/>
    <!-- here some more

    and than i need to select these -->
    <a href="images/x.jpg"  ><a/>
    <a href="images/x.jpg"  ><a/>
    <a href="images/x.jpg"  ><a/>

</div> 

所以现在我需要这样的东西：

so now i need some thing like this:

#something a:last-child{
   /* only now it needs to select 2 more a's that are before this child */ 
}

推荐答案

您可以阅读更多这里关于第n个最后一个孩子，但这应该基本上选择最后3个孩子只有CSS

You can read more here about nth-last child, but this should basically do the trick of selecting the last 3 children with just CSS

#something a:nth-last-child(-n+3) {
    /*declarations*/
}

FabrícioMatté

这只会选择返回正数的行表达式（-n + 3），因为我们使用nth-last-child，所以从最后到第一个数字，
，所以从底部开始的第一行给出，

This will only select those rows returning a positive number for out N expression (-n+3), and since we are using nth-last-child, it's counting from last to first, so first rows from bottom gives,

f(n) = -n+3
f(1) = -1+3 = 2 <- first row from the bottom
f(2) = -2+3 = 1 <- second row from the bottom
f(3) = -3+3 = 0 <- third row from the bottom

其他一切将返回负数

这篇关于选择最后3个子节点的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！