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<h1 id="firstHeading" class="firstHeading">wcsncmp</h1> <table class="t-dcl-begin"> <tr class="t-dsc-header"> <th> Defined in header <code><wchar.h></code> </th> <th> </th> <th> </th> </tr> <tr class="t-dcl"> <td> <pre data-language="c">int wcsncmp( const wchar_t* lhs, const wchar_t* rhs, size_t count );</pre>
</td> <td class="t-dcl-nopad"> </td> <td> <span class="t-mark-rev t-since-c95">(since C95)</span> </td> </tr> </table> <p>Compares at most <code>count</code> wide characters of two null-terminated wide strings. The comparison is done lexicographically.</p>
<p>The sign of the result is the sign of the difference between the values of the first pair of wide characters that differ in the strings being compared.</p>
<p>The behavior is undefined if <code>lhs</code> or <code>rhs</code> are not pointers to null-terminated strings.</p>
<h3 id="Parameters"> Parameters</h3> <table class="t-par-begin"> <tr class="t-par"> <td> lhs, rhs </td> <td> - </td> <td> pointers to the null-terminated wide strings to compare </td>
</tr> <tr class="t-par"> <td> count </td> <td> - </td> <td> maximum number of characters to compare </td>
</tr>
</table> <h3 id="Return_value"> Return value</h3> <p>Negative value if <code>lhs</code> appears before <code>rhs</code> in lexicographical order.</p>
<p>Zero if <code>lhs</code> and <code>rhs</code> compare equal.</p>
<p>Positive value if <code>lhs</code> appears after <code>rhs</code> in lexicographical order.</p>
<h3 id="Notes"> Notes</h3> <p>This function is not locale-sensitive, unlike <code><a href="wcscoll" title="c/string/wide/wcscoll">wcscoll</a></code> and <code><a href="wcsxfrm" title="c/string/wide/wcsxfrm">wcsxfrm</a></code>.</p>
<h3 id="Example"> Example</h3> <div class="t-example"> <div class="c source-c"><pre data-language="c">#include <stdio.h>
#include <wchar.h>
#include <locale.h>
void demo(const wchar_t *lhs, const wchar_t *rhs, int sz)
{
int rc = wcsncmp(lhs, rhs, sz);
if(rc == 0)
printf("First %d characters of [%ls] equal [%ls]\n", sz, lhs, rhs);
else if(rc < 0)
printf("First %d characters of [%ls] precede [%ls]\n", sz, lhs, rhs);
else if(rc > 0)
printf("First %d characters of [%ls] follow [%ls]\n", sz, lhs, rhs);
}
int main(void)
{
const wchar_t *str1 = L"안녕하세요";
const wchar_t *str2 = L"안녕히 가십시오";
setlocale(LC_ALL, "en_US.utf8");
demo(str1, str2, 5);
demo(str2, str1, 8);
demo(str1, str2, 2);
}</pre></div> <p>Output:</p>
<div class="text source-text"><pre data-language="c">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> <h3 id="References"> References</h3> <ul>
<li> C11 standard (ISO/IEC 9899:2011): </li>
<ul><li> 7.29.4.4.3 The wcsncmp function (p: 434) </li></ul>
<li> C99 standard (ISO/IEC 9899:1999): </li>
<ul><li> 7.24.4.4.3 The wcsncmp function (p: 380) </li></ul>
</ul> <h3 id="See_also"> See also</h3> <table class="t-dsc-begin"> <tr class="t-dsc"> <td> <div><a href="wcscmp" title="c/string/wide/wcscmp"> <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> </td> <td> compares two wide strings <br> <span class="t-mark">(function)</span> </td>
</tr> <tr class="t-dsc"> <td> <div><a href="wmemcmp" title="c/string/wide/wmemcmp"> <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> </td> <td> compares a certain amount of wide characters from two arrays <br> <span class="t-mark">(function)</span> </td>
</tr> <tr class="t-dsc"> <td> <div><a href="wcscoll" title="c/string/wide/wcscoll"> <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> </td> <td> compares two wide strings in accordance to the current locale <br> <span class="t-mark">(function)</span> </td>
</tr> <tr class="t-dsc"> <td colspan="2"> <span><a href="https://en.cppreference.com/w/cpp/string/wide/wcsncmp" title="cpp/string/wide/wcsncmp">C++ documentation</a></span> for <code>wcsncmp</code> </td>
</tr> </table> <div class="_attribution">
<p class="_attribution-p">
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<a href="https://en.cppreference.com/w/c/string/wide/wcsncmp" class="_attribution-link">https://en.cppreference.com/w/c/string/wide/wcsncmp</a>
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