mirror of
https://github.com/fofolee/uTools-Manuals.git
synced 2025-06-08 15:04:05 +08:00
184 lines
26 KiB
HTML
184 lines
26 KiB
HTML
<article class="" id="post-">
|
||
<header class="entry-header">
|
||
<h1 class="entry-title">:nth-child() Selector</h1>
|
||
<div class="entry-meta">
|
||
所属分类：<span class="category"><a href="/category/selectors/">选择器</a> > <a href="/category/selectors/child-filter-selectors/">子元素过滤</a></span>
|
||
<span class="pull-right">英文文档：<a href="https://api.jquery123.com/nth-child-selector/" target="_blank">:nth-child() Selector</a></span>
|
||
</div><!-- .entry-meta -->
|
||
</header><!-- .entry-header -->
|
||
<!-- .entry-header -->
|
||
<div class="entry-content">
|
||
<article class="entry selector" id="nth-child1"><h2 class="section-title"><span>nth-child selector</span></h2>
|
||
<div class="entry-wrapper">
|
||
<p class="desc"><strong>描述: </strong>选择的他们所有父元素的第n个子元素。</p>
|
||
<ul class="signatures"><li class="signature">
|
||
<h4 class="name">
|
||
<span class="version-details">添加的版本: <a href="/category/version/1.1.4/">1.1.4</a></span>jQuery( ":nth-child(index/even/odd/equation)" )</h4>
|
||
<p class="argument"><strong>index: </strong>每个相匹配子元素的索引值，从<code>1</code>开始，也可以是字符串 <code>even</code> 或 <code>odd</code>，或一个方程式( 例如 <code>:nth-child(even)</code>, <code>:nth-child(4n)</code> )。</p>
|
||
</li></ul>
|
||
<div class="longdesc" id="entry-longdesc">
|
||
<p>因为jQuery的实现<code>:nth-child(n)</code>是严格来自CSS规范，所以<code>n</code>值是“1索引”，也就是说，从1开始计数。对于所有其他选择器表达式，jQuery遵循JavaScript的“0索引”的计数。因此，给定一个单一<code><ul></code>包含两个<code><li></code>， <code>$('li:nth-child(1)')</code>选择第一个<code><li></code>，而<code>$('li:eq(1)')</code>选择第二个。</p>
|
||
<p><code>:nth-child(n)</code>伪类很容易混淆<code>:eq(n)</code>，即使两个可能导致完全不同的匹配的元素。用<code>:nth-child(n)</code>时 ，所有子元素都计算在内，不管它们是什么，并且指定的元素被选中仅匹配连接到伪类选择器。而用<code>:eq(n)</code>时，只有与这个伪类前面的选择相匹配的元素才会被计数（即，成为候选元素），不限于任何其他元素的孩子，而且第（n +1）个一（n是基于0）被选中。</p>
|
||
<p>这个不寻常的用法，可进一步讨论中找到
|
||
<a href="http://www.w3.org/TR/css3-selectors/#nth-child-pseudo">W3C CSS specification</a>.</p>
|
||
<div style=" background-color: #F2F2F2; padding:10px;">
|
||
<h4>注：</h4>
|
||
看下面一个例子：
|
||
<p></p><pre><div class="test"><br/>
|
||
<p>A元素</p><br/>
|
||
<p>B元素</p><br/>
|
||
<div>C元素</div><br/>
|
||
<p>D元素</p><br/>
|
||
</div></pre>
|
||
<p>看下面的代码</p>
|
||
<p></p><pre>
|
||
|
||
$("p:nth-child(2)")//B元素被选中</pre>
|
||
<div>
|
||
<code>p:nth-child(2)</code>选择器选择B元素，<code>p:nth-child(2)</code>选择器要满足的条件是：<ul><li>1、是一个段落p元素；</li>
|
||
<li>2.是父元素的第二个子元素</li></ul>
|
||
上述的HTML结构中，<code><div class="test"></code>的第二个子元素是p元素，所以满足条件，B元素就被中了。
|
||
|
||
</div>
|
||
<p>jQuery 1.9新增了<code>:nth-of-type()</code>选择器，和这个<code>:nth-child()</code>比较容易混淆，具体查看<a href="/nth-of-type-selector/"><code>:nth-of-type()</code></a>中的比较说明</p>
|
||
</div>
|
||
</div>
|
||
<section class="entry-examples" id="entry-examples"><header><h2 class="underline">例子:</h2></header><div class="entry-example" id="example-0">
|
||
<h4>Example: <span class="desc">查找每个匹配的 ul 中的第二个 li，并将它标记出来。</span>
|
||
</h4>
|
||
<div class="syntaxhighlighter xml ">
|
||
<table>
|
||
<tbody>
|
||
<tr>
|
||
<td class="gutter">
|
||
<div class="line n1">1</div>
|
||
<div class="line n2">2</div>
|
||
<div class="line n3">3</div>
|
||
<div class="line n4">4</div>
|
||
<div class="line n5">5</div>
|
||
<div class="line n6">6</div>
|
||
<div class="line n7">7</div>
|
||
<div class="line n8">8</div>
|
||
<div class="line n9">9</div>
|
||
<div class="line n10">10</div>
|
||
<div class="line n11">11</div>
|
||
<div class="line n12">12</div>
|
||
<div class="line n13">13</div>
|
||
<div class="line n14">14</div>
|
||
<div class="line n15">15</div>
|
||
<div class="line n16">16</div>
|
||
<div class="line n17">17</div>
|
||
<div class="line n18">18</div>
|
||
<div class="line n19">19</div>
|
||
<div class="line n20">20</div>
|
||
<div class="line n21">21</div>
|
||
<div class="line n22">22</div>
|
||
<div class="line n23">23</div>
|
||
<div class="line n24">24</div>
|
||
<div class="line n25">25</div>
|
||
<div class="line n26">26</div>
|
||
<div class="line n27">27</div>
|
||
<div class="line n28">28</div>
|
||
<div class="line n29">29</div>
|
||
<div class="line n30">30</div>
|
||
<div class="line n31">31</div>
|
||
<div class="line n32">32</div>
|
||
<div class="line n33">33</div>
|
||
<div class="line n34">34</div>
|
||
<div class="line n35">35</div>
|
||
</td>
|
||
<td class="code">
|
||
<pre><div class="container"><div class="line"><code><span class="doctype"><!DOCTYPE html></span></code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">html</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">head</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">style</span>></span><span class="css"></span></code></div></div><div class="container"><div class="line"><code> <span class="tag">div</span> <span class="rules">{ <span class="rule"><span class="attribute">float</span>:<span class="value">left;</span></span> <span class="rule">}</span></span></code></div></div><div class="container"><div class="line"><code> <span class="tag">span</span> <span class="rules">{ <span class="rule"><span class="attribute">color</span>:<span class="value">blue;</span></span> <span class="rule">}</span></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"></<span class="title">style</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">script</span> <span class="attribute">src</span>=<span class="value">"https://code.jquery.com/jquery-latest.js"</span>></span><span class="javascript"></span><span class="tag"></<span class="title">script</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">head</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">body</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">ul</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">li</span>></span>John<span class="tag"></<span class="title">li</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">li</span>></span>Karl<span class="tag"></<span class="title">li</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">li</span>></span>Brandon<span class="tag"></<span class="title">li</span>></span></code></div></div><div class="container"><div class="line"><code> </code></div></div><div class="container"><div class="line"><code> <span class="tag"></<span class="title">ul</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">ul</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">li</span>></span>Sam<span class="tag"></<span class="title">li</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"></<span class="title">ul</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">ul</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">li</span>></span>Glen<span class="tag"></<span class="title">li</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">li</span>></span>Tane<span class="tag"></<span class="title">li</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">li</span>></span>Ralph<span class="tag"></<span class="title">li</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">li</span>></span>David<span class="tag"></<span class="title">li</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"></<span class="title">ul</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">script</span>></span><span class="javascript">$(<span class="string">"ul li:nth-child(2)"</span>).append(<span class="string">"<span> - 2nd!</span>"</span>);</span><span class="tag"></<span class="title">script</span>></span></code></div></div><div class="container"><div class="line"><code> </code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">body</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">html</span>></span></code></div></div></pre>
|
||
</td>
|
||
</tr>
|
||
</tbody>
|
||
</table>
|
||
</div>
|
||
<h4>Demo:</h4>
|
||
<div class="demo code-demo"></div>
|
||
</div>
|
||
<div class="entry-example" id="example-1">
|
||
<h4>Example: <span class="desc">这个例子展示了刚才提到的两个容易混淆的选择器是如何工作的。注意这里的 :even 和 :odd 会无视它们的父元素，而仅仅把元素列表中的元素每隔一个过滤出来。而 :nth-child 则会计算子元素在各自父元素中的索引值。很多时候，直接看例子会比空讲要容易理解的多...</span>
|
||
</h4>
|
||
<div class="syntaxhighlighter xml ">
|
||
<table>
|
||
<tbody>
|
||
<tr>
|
||
<td class="gutter">
|
||
<div class="line n1">1</div>
|
||
<div class="line n2">2</div>
|
||
<div class="line n3">3</div>
|
||
<div class="line n4">4</div>
|
||
<div class="line n5">5</div>
|
||
<div class="line n6">6</div>
|
||
<div class="line n7">7</div>
|
||
<div class="line n8">8</div>
|
||
<div class="line n9">9</div>
|
||
<div class="line n10">10</div>
|
||
<div class="line n11">11</div>
|
||
<div class="line n12">12</div>
|
||
<div class="line n13">13</div>
|
||
<div class="line n14">14</div>
|
||
<div class="line n15">15</div>
|
||
<div class="line n16">16</div>
|
||
<div class="line n17">17</div>
|
||
<div class="line n18">18</div>
|
||
<div class="line n19">19</div>
|
||
<div class="line n20">20</div>
|
||
<div class="line n21">21</div>
|
||
<div class="line n22">22</div>
|
||
<div class="line n23">23</div>
|
||
<div class="line n24">24</div>
|
||
<div class="line n25">25</div>
|
||
<div class="line n26">26</div>
|
||
<div class="line n27">27</div>
|
||
<div class="line n28">28</div>
|
||
<div class="line n29">29</div>
|
||
<div class="line n30">30</div>
|
||
<div class="line n31">31</div>
|
||
<div class="line n32">32</div>
|
||
<div class="line n33">33</div>
|
||
<div class="line n34">34</div>
|
||
<div class="line n35">35</div>
|
||
<div class="line n36">36</div>
|
||
<div class="line n37">37</div>
|
||
<div class="line n38">38</div>
|
||
<div class="line n39">39</div>
|
||
<div class="line n40">40</div>
|
||
<div class="line n41">41</div>
|
||
<div class="line n42">42</div>
|
||
<div class="line n43">43</div>
|
||
<div class="line n44">44</div>
|
||
<div class="line n45">45</div>
|
||
<div class="line n46">46</div>
|
||
<div class="line n47">47</div>
|
||
<div class="line n48">48</div>
|
||
<div class="line n49">49</div>
|
||
<div class="line n50">50</div>
|
||
<div class="line n51">51</div>
|
||
<div class="line n52">52</div>
|
||
<div class="line n53">53</div>
|
||
<div class="line n54">54</div>
|
||
<div class="line n55">55</div>
|
||
<div class="line n56">56</div>
|
||
<div class="line n57">57</div>
|
||
<div class="line n58">58</div>
|
||
<div class="line n59">59</div>
|
||
<div class="line n60">60</div>
|
||
<div class="line n61">61</div>
|
||
<div class="line n62">62</div>
|
||
<div class="line n63">63</div>
|
||
<div class="line n64">64</div>
|
||
</td>
|
||
<td class="code">
|
||
<pre><div class="container"><div class="line"><code><span class="doctype"><!DOCTYPE html></span></code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">html</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">head</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">style</span>></span><span class="css"></span></code></div></div><div class="container"><div class="line"><code><span class="tag">button</span> <span class="rules">{ <span class="rule"><span class="attribute">display</span>:<span class="value">block;</span></span> <span class="rule"><span class="attribute">font-size</span>:<span class="value"><span class="number">12</span>px;</span></span> <span class="rule"><span class="attribute">width</span>:<span class="value"><span class="number">100</span>px;</span></span> <span class="rule">}</span></span></code></div></div><div class="container"><div class="line"><code><span class="tag">div</span> <span class="rules">{ <span class="rule"><span class="attribute">float</span>:<span class="value">left;</span></span> <span class="rule"><span class="attribute">margin</span>:<span class="value"><span class="number">10</span>px;</span></span> <span class="rule"><span class="attribute">font-size</span>:<span class="value"><span class="number">10</span>px;</span></span></span></code></div></div><div class="container"><div class="line"><code> <span class="rule"><span class="attribute">border</span>:<span class="value"><span class="number">1</span>px solid black;</span></span> <span class="rule">}</span></code></div></div><div class="container"><div class="line"><code><span class="tag">span</span> <span class="rules">{ <span class="rule"><span class="attribute">color</span>:<span class="value">blue;</span></span> <span class="rule"><span class="attribute">font-size</span>:<span class="value"><span class="number">18</span>px;</span></span> <span class="rule">}</span></span></code></div></div><div class="container"><div class="line"><code><span class="id">#inner</span> <span class="rules">{ <span class="rule"><span class="attribute">color</span>:<span class="value">red;</span></span> <span class="rule">}</span></span></code></div></div><div class="container"><div class="line"><code><span class="tag">td</span> <span class="rules">{ <span class="rule"><span class="attribute">width</span>:<span class="value"><span class="number">50</span>px;</span></span> <span class="rule"><span class="attribute">text-align</span>:<span class="value">center;</span></span> <span class="rule">}</span></span></code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">style</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">script</span> <span class="attribute">src</span>=<span class="value">"https://code.jquery.com/jquery-latest.js"</span>></span><span class="javascript"></span><span class="tag"></<span class="title">script</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">head</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">body</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">button</span>></span>:nth-child(even)<span class="tag"></<span class="title">button</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">button</span>></span>:nth-child(odd)<span class="tag"></<span class="title">button</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">button</span>></span>:nth-child(3n)<span class="tag"></<span class="title">button</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">button</span>></span>:nth-child(2)<span class="tag"></<span class="title">button</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">button</span>></span>:nth-child(3n+1)<span class="tag"></<span class="title">button</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">button</span>></span>:nth-child(3n+2)<span class="tag"></<span class="title">button</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">button</span>></span>:even<span class="tag"></<span class="title">button</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">button</span>></span>:odd<span class="tag"></<span class="title">button</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code> </code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">table</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">tr</span>></span><span class="tag"><<span class="title">td</span>></span>John<span class="tag"></<span class="title">td</span>></span><span class="tag"></<span class="title">tr</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">tr</span>></span><span class="tag"><<span class="title">td</span>></span>Karl<span class="tag"></<span class="title">td</span>></span><span class="tag"></<span class="title">tr</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">tr</span>></span><span class="tag"><<span class="title">td</span>></span>Brandon<span class="tag"></<span class="title">td</span>></span><span class="tag"></<span class="title">tr</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">tr</span>></span><span class="tag"><<span class="title">td</span>></span>Benjamin<span class="tag"></<span class="title">td</span>></span><span class="tag"></<span class="title">tr</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"></<span class="title">table</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">table</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">tr</span>></span><span class="tag"><<span class="title">td</span>></span>Sam<span class="tag"></<span class="title">td</span>></span><span class="tag"></<span class="title">tr</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"></<span class="title">table</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">table</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">tr</span>></span><span class="tag"><<span class="title">td</span>></span>Glen<span class="tag"></<span class="title">td</span>></span><span class="tag"></<span class="title">tr</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">tr</span>></span><span class="tag"><<span class="title">td</span>></span>Tane<span class="tag"></<span class="title">td</span>></span><span class="tag"></<span class="title">tr</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">tr</span>></span><span class="tag"><<span class="title">td</span>></span>Ralph<span class="tag"></<span class="title">td</span>></span><span class="tag"></<span class="title">tr</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">tr</span>></span><span class="tag"><<span class="title">td</span>></span>David<span class="tag"></<span class="title">td</span>></span><span class="tag"></<span class="title">tr</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">tr</span>></span><span class="tag"><<span class="title">td</span>></span>Mike<span class="tag"></<span class="title">td</span>></span><span class="tag"></<span class="title">tr</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"><<span class="title">tr</span>></span><span class="tag"><<span class="title">td</span>></span>Dan<span class="tag"></<span class="title">td</span>></span><span class="tag"></<span class="title">tr</span>></span></code></div></div><div class="container"><div class="line"><code> <span class="tag"></<span class="title">table</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">div</span>></span></code></div></div><div class="container"><div class="line"><code> </code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">span</span>></span>tr<span class="tag"><<span class="title">span</span> <span class="attribute">id</span>=<span class="value">"inner"</span>></span><span class="tag"></<span class="title">span</span>></span><span class="tag"></<span class="title">span</span>></span></code></div></div><div class="container"><div class="line"><code> </code></div></div><div class="container"><div class="line"><code><span class="tag"><<span class="title">script</span>></span><span class="javascript"></span></code></div></div><div class="container"><div class="line"><code>$(<span class="string">"button"</span>).click(<span class="function"><span class="keyword">function</span> <span class="params">()</span> {</span></code></div></div><div class="container"><div class="line"><code> <span class="keyword">var</span> str = $(<span class="keyword">this</span>).text();</code></div></div><div class="container"><div class="line"><code> $(<span class="string">"tr"</span>).css(<span class="string">"background"</span>, <span class="string">"white"</span>);</code></div></div><div class="container"><div class="line"><code> $(<span class="string">"tr"</span> + str).css(<span class="string">"background"</span>, <span class="string">"#ff0000"</span>);</code></div></div><div class="container"><div class="line"><code> $(<span class="string">"#inner"</span>).text(str);</code></div></div><div class="container"><div class="line"><code>});</code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">script</span>></span></code></div></div><div class="container"><div class="line"><code> </code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">body</span>></span></code></div></div><div class="container"><div class="line"><code><span class="tag"></<span class="title">html</span>></span></code></div></div></pre>
|
||
</td>
|
||
</tr>
|
||
</tbody>
|
||
</table>
|
||
</div>
|
||
<h4>Demo:</h4>
|
||
<div class="demo code-demo"></div>
|
||
</div></section>
|
||
</div></article> </div>
|
||
</article> |