/php/function.substr-count.html
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- <title>计算字串出现的次数</title>
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- </div><hr /><div id="function.substr-count" class="refentry">
- <div class="refnamediv">
- <h1 class="refname">substr_count</h1>
- <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">substr_count</span> — <span class="dc-title">计算字串出现的次数</span></p>
- </div>
- <div class="refsect1 description" id="refsect1-function.substr-count-description">
- <h3 class="title">说明</h3>
- <div class="methodsynopsis dc-description">
- <span class="type">int</span> <span class="methodname"><strong>substr_count</strong></span>
- ( <span class="methodparam"><span class="type">string</span> <code class="parameter">$haystack</code></span>
- , <span class="methodparam"><span class="type">string</span> <code class="parameter">$needle</code></span>
- [, <span class="methodparam"><span class="type">int</span> <code class="parameter">$offset</code><span class="initializer"> = 0</span></span>
- [, <span class="methodparam"><span class="type">int</span> <code class="parameter">$length</code></span>
- ]] )</div>
- <p class="para rdfs-comment">
- <span class="function"><strong>substr_count()</strong></span> 返回子字符串<em><code class="parameter">needle</code></em> 在字符串 <em><code class="parameter">haystack</code></em> 中出现的次数。注意 <em><code class="parameter">needle</code></em> 区分大小写。
- </p>
- <blockquote class="note"><p><strong class="note">Note</strong>:
- <p class="para">
- 该函数不会计算重叠字符串。参见下面的例子。
- </p>
- </p></blockquote>
- </div>
- <div class="refsect1 parameters" id="refsect1-function.substr-count-parameters">
- <h3 class="title">参数</h3>
- <p class="para">
- <dl>
- <dt>
- <span class="term"><em><code class="parameter">haystack</code></em></span>
- <dd>
- <p class="para">
- 在此字符串中进行搜索。
- </p>
- </dd>
- </dt>
- <dt>
- <span class="term"><em><code class="parameter">needle</code></em></span>
- <dd>
- <p class="para">
- 要搜索的字符串。
- </p>
- </dd>
- </dt>
- <dt>
- <span class="term"><em><code class="parameter">offset</code></em></span>
- <dd>
- <p class="para">
- 开始计数的偏移位置。
- </p>
- </dd>
- </dt>
- <dt>
- <span class="term"><em><code class="parameter">length</code></em></span>
- <dd>
- <p class="para">
- 指定偏移位置之后的最大搜索长度。如果偏移量加上这个长度的和大于 <em><code class="parameter">haystack</code></em> 的总长度,则打印警告信息。
- </p>
- </dd>
- </dt>
- </dl>
- </p>
- </div>
- <div class="refsect1 returnvalues" id="refsect1-function.substr-count-returnvalues">
- <h3 class="title">返回值</h3>
- <p class="para">
- 该函数返回<span class="type"><span class="type 整型">整型</span></span>。
- </p>
- </div>
- <div class="refsect1 changelog" id="refsect1-function.substr-count-changelog">
- <h3 class="title">更新日志</h3>
- <p class="para">
- <table class="doctable informaltable">
-
- <thead>
- <tr>
- <th>版本</th>
- <th>说明</th>
- </tr>
- </thead>
- <tbody class="tbody">
- <tr>
- <td>5.1.0</td>
- <td>
- 新增 <em><code class="parameter">offset</code></em> 和 <em><code class="parameter">length</code></em> 参数。
- </td>
- </tr>
- </tbody>
-
- </table>
- </p>
- </div>
- <div class="refsect1 examples" id="refsect1-function.substr-count-examples">
- <h3 class="title">范例</h3>
- <p class="para">
- <div class="example" id="example-4672">
- <p><strong>Example #1 <span class="function"><strong>substr_count()</strong></span> 范例</strong></p>
- <div class="example-contents">
- <div class="phpcode"><code><span style="color: #000000">
- <span style="color: #0000BB"><?php<br />$text </span><span style="color: #007700">= </span><span style="color: #DD0000">'This is a test'</span><span style="color: #007700">;<br />echo </span><span style="color: #0000BB">strlen</span><span style="color: #007700">(</span><span style="color: #0000BB">$text</span><span style="color: #007700">); </span><span style="color: #FF8000">// 14<br /><br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">substr_count</span><span style="color: #007700">(</span><span style="color: #0000BB">$text</span><span style="color: #007700">, </span><span style="color: #DD0000">'is'</span><span style="color: #007700">); </span><span style="color: #FF8000">// 2<br /><br />// 字符串被简化为 's is a test',因此输出 1<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">substr_count</span><span style="color: #007700">(</span><span style="color: #0000BB">$text</span><span style="color: #007700">, </span><span style="color: #DD0000">'is'</span><span style="color: #007700">, </span><span style="color: #0000BB">3</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// 字符串被简化为 's i',所以输出 0<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">substr_count</span><span style="color: #007700">(</span><span style="color: #0000BB">$text</span><span style="color: #007700">, </span><span style="color: #DD0000">'is'</span><span style="color: #007700">, </span><span style="color: #0000BB">3</span><span style="color: #007700">, </span><span style="color: #0000BB">3</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// 因为 5+10 > 14,所以生成警告<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">substr_count</span><span style="color: #007700">(</span><span style="color: #0000BB">$text</span><span style="color: #007700">, </span><span style="color: #DD0000">'is'</span><span style="color: #007700">, </span><span style="color: #0000BB">5</span><span style="color: #007700">, </span><span style="color: #0000BB">10</span><span style="color: #007700">);<br /><br /><br /></span><span style="color: #FF8000">// 输出 1,因为该函数不计算重叠字符串<br /></span><span style="color: #0000BB">$text2 </span><span style="color: #007700">= </span><span style="color: #DD0000">'gcdgcdgcd'</span><span style="color: #007700">;<br />echo </span><span style="color: #0000BB">substr_count</span><span style="color: #007700">(</span><span style="color: #0000BB">$text2</span><span style="color: #007700">, </span><span style="color: #DD0000">'gcdgcd'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span>
- </span>
- </code></div>
- </div>
- </div>
- </p>
- </div>
- <div class="refsect1 seealso" id="refsect1-function.substr-count-seealso">
- <h3 class="title">参见</h3>
- <p class="para">
- <ul class="simplelist">
- <li class="member"> <span class="function"><a href="function.count-chars.html" class="function" rel="rdfs-seeAlso">count_chars()</a> - 返回字符串所用字符的信息</span></li>
- <li class="member"> <span class="function"><a href="function.strpos.html" class="function" rel="rdfs-seeAlso">strpos()</a> - 查找字符串首次出现的位置</span></li>
- <li class="member"> <span class="function"><a href="function.substr.html" class="function" rel="rdfs-seeAlso">substr()</a> - 返回字符串的子串</span></li>
- <li class="member"> <span class="function"><a href="function.strstr.html" class="function" rel="rdfs-seeAlso">strstr()</a> - 查找字符串的首次出现</span></li>
- </ul>
- </p>
- </div>
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