165 lines
9.7 KiB
HTML
165 lines
9.7 KiB
HTML
<!DOCTYPE html>
|
|
<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
|
|
<head><meta http-equiv="x-ua-compatible" content="ie=edge">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
|
<title>wcsncmp</title>
|
|
<link rel="stylesheet" href="ext.css" />
|
|
<link rel="stylesheet" href="site_modules.css" />
|
|
</head>
|
|
<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-c_string_wide_wcsncmp skin-cppreference2 action-view cpp-navbar">
|
|
<div id="cpp-content-base">
|
|
<div id="content"><a id="top"></a>
|
|
<h1 id="firstHeading" class="firstHeading">wcsncmp</h1>
|
|
<div id="bodyContent">
|
|
<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>
|
|
<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
|
|
<table class="t-dcl-begin">
|
|
<tbody>
|
|
<tr class="t-dsc-header">
|
|
<td>
|
|
<div>定义于头文件 <code><wchar.h></code></div>
|
|
</td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-c95">
|
|
<td>
|
|
<div><span class="mw-geshi c source-c"><span class="kw4">int</span> wcsncmp<span class="br0">(</span> <span class="kw4">const</span> <span class="kw4">wchar_t</span><span class="sy2">*</span> lhs, <span class="kw4">const</span> <span class="kw4">wchar_t</span><span class="sy2">*</span> rhs, <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>
|
|
</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
<td><span class="t-mark-rev t-since-c95">(C95 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl-sep">
|
|
<td></td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<p>比较二个空终止宽字符串的至多 <code>count</code> 个字符。按字典序进行比较。</p>
|
|
<p>结果的符号是被比较的字符串中首对宽字符的值间的差的符号。</p>
|
|
<p>若 <code>lhs</code> 或 <code>rhs</code> 不是指向空终止字符串的指针则行为未定义。</p>
|
|
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">参数</span></h3>
|
|
<table class="t-par-begin">
|
|
<tr class="t-par">
|
|
<td>lhs, rhs</td>
|
|
<td>-</td>
|
|
<td>指向要比较的空终止宽字符串的指针</td>
|
|
</tr>
|
|
<tr class="t-par">
|
|
<td>count</td>
|
|
<td>-</td>
|
|
<td>要比较的最大字符数</td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
|
|
<p>若字典序中 <code>lhs</code> 先出现于 <code>rhs</code> 则为负值。</p>
|
|
<p>若 <code>lhs</code> 与 <code>rhs</code> 比较相等，或若 count 为零，则为零。</p>
|
|
<p>若字典序中 <code>lhs</code> 后出现于 <code>rhs</code> 则为负值。</p>
|
|
<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">注意</span></h3>
|
|
<p>不同于 <span class="t-lc"><a href="c-string-wide-wcscoll.html">wcscoll</a></span> 和 <span class="t-lc"><a href="c-string-wide-wcsxfrm.html">wcsxfrm</a></span> ，此函数不考虑本地环境。</p>
|
|
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
|
|
<div class="t-example">
|
|
<div class="t-example-live-link"></div>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="c source-c">
|
|
<pre class="de1"><span class="co2">#include <stdio.h></span>
|
|
<span class="co2">#include <wchar.h></span>
|
|
<span class="co2">#include <locale.h></span>
|
|
|
|
<span class="kw4">void</span> demo<span class="br0">(</span><span class="kw4">const</span> <span class="kw4">wchar_t</span> <span class="sy2">*</span>lhs, <span class="kw4">const</span> <span class="kw4">wchar_t</span> <span class="sy2">*</span>rhs, <span class="kw4">int</span> sz<span class="br0">)</span>
|
|
<span class="br0">{</span>
|
|
<span class="kw4">int</span> rc <span class="sy1">=</span> wcsncmp<span class="br0">(</span>lhs, rhs, sz<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw1">if</span><span class="br0">(</span>rc <span class="sy1">==</span> <span class="nu0">0</span><span class="br0">)</span>
|
|
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">"First %d characters of [%ls] equal [%ls]<span class="es1">\n</span>"</span>, sz, lhs, rhs<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw1">else</span> <span class="kw1">if</span><span class="br0">(</span>rc <span class="sy1"><</span> <span class="nu0">0</span><span class="br0">)</span>
|
|
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">"First %d characters of [%ls] precede [%ls]<span class="es1">\n</span>"</span>, sz, lhs, rhs<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw1">else</span> <span class="kw1">if</span><span class="br0">(</span>rc <span class="sy1">></span> <span class="nu0">0</span><span class="br0">)</span>
|
|
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">"First %d characters of [%ls] follow [%ls]<span class="es1">\n</span>"</span>, sz, lhs, rhs<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="br0">}</span>
|
|
|
|
<span class="kw4">int</span> main<span class="br0">(</span><span class="kw4">void</span><span class="br0">)</span>
|
|
<span class="br0">{</span>
|
|
<span class="kw4">const</span> <span class="kw4">wchar_t</span> <span class="sy2">*</span>str1 <span class="sy1">=</span> L<span class="st0">"안녕하세요"</span><span class="sy4">;</span>
|
|
<span class="kw4">const</span> <span class="kw4">wchar_t</span> <span class="sy2">*</span>str2 <span class="sy1">=</span> L<span class="st0">"안녕히 가십시오"</span><span class="sy4">;</span>
|
|
|
|
<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>
|
|
demo<span class="br0">(</span>str1, str2, <span class="nu0">5</span><span class="br0">)</span><span class="sy4">;</span>
|
|
demo<span class="br0">(</span>str2, str1, <span class="nu0">8</span><span class="br0">)</span><span class="sy4">;</span>
|
|
demo<span class="br0">(</span>str1, str2, <span class="nu0">2</span><span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="br0">}</span></pre></div>
|
|
</div>
|
|
<p>输出：</p>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="text source-text">
|
|
<pre class="de1">First 5 characters of [안녕하세요] precede [안녕히 가십시오]
|
|
First 8 characters of [안녕히 가십시오] follow [안녕하세요]
|
|
First 2 characters of [안녕하세요] equal [안녕히 가십시오]</pre></div>
|
|
</div>
|
|
</div>
|
|
<h3><span class="mw-headline" id=".E5.BC.95.E7.94.A8">引用</span></h3>
|
|
<div class="t-ref-std-11">
|
|
<ul>
|
|
<li>C11 标准（ISO/IEC 9899:2011）：</li>
|
|
</ul>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.29.4.4.3 The wcsncmp function (p: 434)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<div class="t-ref-std-c99">
|
|
<ul>
|
|
<li>C99 标准（ISO/IEC 9899:1999）：</li>
|
|
</ul>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.24.4.4.3 The wcsncmp function (p: 380)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="c-string-wide-wcscmp.html"><span class="t-lines"><span>wcscmp</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c95">(C95)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>比较两个宽字符串<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="c-string-wide-wmemcmp.html"><span class="t-lines"><span>wmemcmp</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c95">(C95)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>比较两个数组中一定数量的宽字符<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="c-string-wide-wcscoll.html"><span class="t-lines"><span>wcscoll</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c95">(C95)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>根据当前本地环境比较两个宽字符串<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|