144 lines
6.9 KiB
HTML
144 lines
6.9 KiB
HTML
<!DOCTYPE html>
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<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
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<head><meta http-equiv="x-ua-compatible" content="ie=edge">
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
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<title>wmemchr</title>
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<link rel="stylesheet" href="ext.css" />
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<link rel="stylesheet" href="site_modules.css" />
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</head>
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<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-c_string_wide_wmemchr skin-cppreference2 action-view cpp-navbar">
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<div id="cpp-content-base">
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<div id="content"><a id="top"></a>
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<h1 id="firstHeading" class="firstHeading">wmemchr</h1>
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<div id="bodyContent">
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<div id="contentSub"><span class="subpages">< <a href="c.html">c</a>‎ | <a href="c-string.html">string</a>‎ | <a href="c-string-wide.html">wide</a></span></div>
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<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
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<table class="t-dcl-begin">
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<tbody>
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<tr class="t-dsc-header">
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<td>
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<div>定义于头文件 <code><wchar.h></code></div>
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</td>
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<td></td>
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<td></td>
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</tr>
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<tr class="t-dcl">
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<td>
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<div><span class="mw-geshi c source-c"><span class="kw4">wchar_t</span> <span class="sy2">*</span>wmemchr<span class="br0">(</span> <span class="kw4">const</span> <span class="kw4">wchar_t</span> <span class="sy2">*</span>ptr, <span class="kw4">wchar_t</span> ch, <a href="c-types-size_t.html"><span class="kw100">size_t</span></a> count <span class="br0">)</span><span class="sy4">;</span></span></div>
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</td>
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<td class="t-dcl-nopad"></td>
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<td><span class="t-mark-rev t-since-c95">(C95 起)</span></td>
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</tr>
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<tr class="t-dcl-sep">
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<td></td>
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<td></td>
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<td></td>
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</tr>
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</tbody>
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</table>
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<p>于 <code>ptr</code> 所指向的宽字符数组或任何兼容类型的整数数组的首 <code>count</code> 个宽字符中，定位宽字符 <code>ch</code> 的首次出现。</p>
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<p>若 <code>count</code> 为零，则函数返回空指针。</p>
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<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">参数</span></h3>
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<table class="t-par-begin">
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<tr class="t-par">
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<td>ptr</td>
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<td>-</td>
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<td>指向要检验的宽字符数组的指针</td>
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</tr>
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<tr class="t-par">
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<td>ch</td>
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<td>-</td>
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<td>要搜索的宽字符</td>
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</tr>
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<tr class="t-par">
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<td>count</td>
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<td>-</td>
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<td>要检验的宽字符数</td>
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</tr>
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</table>
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<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
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<p>指向宽字符位置的指针，或若找不到这种字符则为空指针。</p>
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<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
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<div class="t-example">
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<div class="t-example-live-link"></div>
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<div dir="ltr" class="mw-geshi" style="text-align: left;">
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<div class="c source-c">
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<pre class="de1"><span class="co2">#include <stdio.h></span>
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<span class="co2">#include <wchar.h></span>
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<span class="co2">#include <locale.h></span>
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<span class="kw4">int</span> main<span class="br0">(</span><span class="kw4">void</span><span class="br0">)</span>
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<span class="br0">{</span>
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<span class="kw4">wchar_t</span> str<span class="br0">[</span><span class="br0">]</span> <span class="sy1">=</span> L<span class="st0">"诺不轻信，故人不负我<span class="es5">\0</span>诺不轻许，故我不负人。"</span><span class="sy4">;</span>
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<a href="c-types-size_t.html"><span class="kw100">size_t</span></a> sz <span class="sy1">=</span> <span class="kw4">sizeof</span> str <span class="sy2">/</span> <span class="kw4">sizeof</span> <span class="sy2">*</span>str<span class="sy4">;</span>
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<span class="kw4">wchar_t</span> target <span class="sy1">=</span> L<span class="st0">'许'</span><span class="sy4">;</span>
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<span class="kw4">wchar_t</span><span class="sy2">*</span> result <span class="sy1">=</span> wmemchr<span class="br0">(</span>str, target, sz<span class="br0">)</span><span class="sy4">;</span>
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<span class="kw1">if</span> <span class="br0">(</span>result<span class="br0">)</span> <span class="br0">{</span>
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<a href="c-locale-setlocale.html"><span class="kw900">setlocale</span></a><span class="br0">(</span><a href="c-locale-LC_categories.html"><span class="kw903">LC_ALL</span></a>, <span class="st0">"en_US.utf8"</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">"Found '%lc' at position %td<span class="es1">\n</span>"</span>,target, result <span class="sy2">-</span> str<span class="br0">)</span><span class="sy4">;</span>
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<span class="br0">}</span>
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<span class="br0">}</span></pre></div>
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</div>
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<p>可能的输出：</p>
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<div dir="ltr" class="mw-geshi" style="text-align: left;">
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<div class="text source-text">
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<pre class="de1">Found '许' at position 14</pre></div>
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</div>
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</div>
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<h3><span class="mw-headline" id=".E5.BC.95.E7.94.A8">引用</span></h3>
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<div class="t-ref-std-11">
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<ul>
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<li>C11 标准（ISO/IEC 9899:2011）：</li>
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</ul>
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<dl>
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<dd>
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<ul>
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<li>7.29.4.5.8 The wmemchr function (p: 438)</li>
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</ul>
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</dd>
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</dl>
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<div class="t-ref-std-c99">
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<ul>
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<li>C99 标准（ISO/IEC 9899:1999）：</li>
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</ul>
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<dl>
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<dd>
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<ul>
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<li>7.24.4.5.8 The wmemchr function (p: 384)</li>
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</ul>
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</dd>
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</dl>
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</div>
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<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
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<table class="t-dsc-begin">
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<tr class="t-dsc">
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<td>
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<div class="t-dsc-member-div">
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<div><a href="c-string-byte-memchr.html"><span class="t-lines"><span>memchr</span></span></a></div>
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</div>
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</td>
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<td>在数组中搜索字符的首次出现<br />
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<span class="t-mark">(函数)</span></td>
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</tr>
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<tr class="t-dsc">
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<td>
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<div class="t-dsc-member-div">
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<div><a href="c-string-wide-wcschr.html"><span class="t-lines"><span>wcschr</span></span></a></div>
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<div><span class="t-lines"><span><span class="t-mark-rev t-since-c95">(C95)</span></span></span></div>
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</div>
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</td>
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<td>查找宽字符在宽字符串中的首次出现<br />
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<span class="t-mark">(函数)</span></td>
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</tr>
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</table>
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</div>
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</div>
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<div class="visualClear"></div>
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</div>
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</div>
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</div>
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</body>
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</html>
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