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<title>round, roundf, roundl, lround, lroundf, lroundl, llround, llroundf, llroundl</title>
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<h1 id="firstHeading" class="firstHeading">round, roundf, roundl, lround, lroundf, lroundl, llround, llroundf, llroundl</h1>
<div id="bodyContent">
<div id="contentSub"><span class="subpages">&lt; <a href="c.html">c</a>&lrm; | <a href="c-numeric.html">numeric</a>&lrm; | <a href="c-numeric-math.html">math</a></span></div>
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<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code>&lt;math.h&gt;</code></div>
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<div><span class="mw-geshi c source-c"><span class="kw4">float</span> &nbsp; &nbsp; &nbsp; roundf<span class="br0">(</span> <span class="kw4">float</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td>(1)</td>
<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<div><span class="mw-geshi c source-c"><span class="kw4">double</span> &nbsp; &nbsp; &nbsp;round<span class="br0">(</span> <span class="kw4">double</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td>(2)</td>
<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> <span class="kw4">double</span> roundl<span class="br0">(</span> <span class="kw4">long</span> <span class="kw4">double</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td>(3)</td>
<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code>&lt;tgmath.h&gt;</code></div>
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<div><span class="mw-geshi c source-c"><span class="co2">#define round( arg )</span></span></div>
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<td>(4)</td>
<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code>&lt;math.h&gt;</code></div>
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> &nbsp; &nbsp; &nbsp;lroundf<span class="br0">(</span> <span class="kw4">float</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td>(5)</td>
<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> &nbsp; &nbsp; &nbsp;lround<span class="br0">(</span> <span class="kw4">double</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td>(6)</td>
<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> &nbsp; &nbsp; &nbsp;lroundl<span class="br0">(</span> <span class="kw4">long</span> <span class="kw4">double</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td>(7)</td>
<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code>&lt;tgmath.h&gt;</code></div>
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<div><span class="mw-geshi c source-c"><span class="co2">#define lround( arg )</span></span></div>
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<td>(8)</td>
<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code>&lt;math.h&gt;</code></div>
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> <span class="kw4">long</span> llroundf<span class="br0">(</span> <span class="kw4">float</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td>(9)</td>
<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> <span class="kw4">long</span> llround<span class="br0">(</span> <span class="kw4">double</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td>(10)</td>
<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> <span class="kw4">long</span> llroundl<span class="br0">(</span> <span class="kw4">long</span> <span class="kw4">double</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td>(11)</td>
<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code>&lt;tgmath.h&gt;</code></div>
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<div><span class="mw-geshi c source-c"><span class="co2">#define llround( arg )</span></span></div>
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<td>(12)</td>
<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<div class="t-li1"><span class="t-li">1-3)</span> &#35745;&#31639;&#19982; <code>arg</code> &#26368;&#37051;&#36817;&#30340;&#25972;&#25968;&#20540;&#65288;&#20197;&#28014;&#28857;&#26684;&#24335;&#65289;&#65292;&#20013;&#28857;&#24773;&#20917;&#21462;&#36828;&#31163;&#38646;&#32773;&#65292;&#26080;&#20851;&#20046;&#24403;&#21069;&#33293;&#20837;&#27169;&#24335;&#12290;</div>
<div class="t-li1"><span class="t-li">5-7, 9-11)</span> &#35745;&#31639;&#19982; <code>arg</code> &#26368;&#37051;&#36817;&#30340;&#25972;&#25968;&#20540;&#65288;&#20197;&#25972;&#25968;&#26684;&#24335;&#65289;&#65292;&#20013;&#28857;&#24773;&#20917;&#21462;&#36828;&#31163;&#38646;&#32773;&#65292;&#26080;&#20851;&#20046;&#24403;&#21069;&#33293;&#20837;&#27169;&#24335;&#12290;</div>
<div class="t-li1"><span class="t-li">4,8,12)</span> &#27867;&#22411;&#23439;&#65306;&#33509; <code>arg</code> &#25317;&#26377; <span class="t-c"><span class="mw-geshi c source-c"><span class="kw4">long</span> <span class="kw4">double</span></span></span> &#31867;&#22411;&#65292;&#21017;&#20998;&#21035;&#35843;&#29992; <code>roundl</code> &#12289; <code>lroundl</code> &#12289; <code>llroundl</code> &#12290;&#21542;&#21017;&#65292;&#33509; <code>arg</code> &#25317;&#26377;&#25972;&#25968;&#31867;&#22411;&#25110; <span class="t-c"><span class="mw-geshi c source-c"><span class="kw4">double</span></span></span> &#31867;&#22411;&#65292;&#21017;&#20998;&#21035;&#35843;&#29992; <code>round</code> &#12289; <code>lround</code> &#12289; <code>llround</code> &#12290;&#21542;&#21017;&#20998;&#21035;&#35843;&#29992; <code>roundf</code>, <code>lroundf</code>, <code>llroundf</code> &#12290;</div>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
<table class="t-par-begin">
<tr class="t-par">
<td>arg</td>
<td>-</td>
<td>&#28014;&#28857;&#20540;</td>
</tr>
</table>
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">&#36820;&#22238;&#20540;</span></h3>
<p>&#33509;&#19981;&#20986;&#29616;&#38169;&#35823;&#65292;&#21017;&#19982;&#36820;&#22238; <code>arg</code> &#30340;&#26368;&#37051;&#36817;&#25972;&#25968;&#20540;&#65292;&#20013;&#28857;&#24773;&#20917;&#21462;&#36828;&#31163;&#38646;&#32773;&#65292;</p>
<div class="t-plot">
<div class="t-plot-left">&#36820;&#22238;&#20540;</div>
<div class="t-plot-image-left"><img alt="math-round away zero.svg" src="math-round_away_zero.svg" width="200" height="200" /></div>
<div class="t-plot-bottom">&#21442;&#25968;</div>
</div>
<p>&#33509;&#20986;&#29616;&#23450;&#20041;&#22495;&#38169;&#35823;&#65292;&#21017;&#36820;&#22238;&#23454;&#29616;&#23450;&#20041;&#20540;&#12290;</p>
<h3><span class="mw-headline" id=".E9.94.99.E8.AF.AF.E5.A4.84.E7.90.86">&#38169;&#35823;&#22788;&#29702;</span></h3>
<p>&#25253;&#21578; <a href="c-numeric-math-math_errhandling.html">math_errhandling</a> &#20013;&#25351;&#23450;&#30340;&#38169;&#35823;&#12290;</p>
<p>&#33509; <code>lround</code> &#25110; <code>llround</code> &#30340;&#32467;&#26524;&#22312;&#36820;&#22238;&#31867;&#22411;&#30340;&#21487;&#34920;&#31034;&#33539;&#22260;&#22806;&#65292;&#21017;&#21487;&#33021;&#20986;&#29616;&#23450;&#20041;&#22495;&#38169;&#35823;&#25110;&#20540;&#22495;&#38169;&#35823;&#12290;</p>
<p>&#33509;&#23454;&#29616;&#25903;&#25345; IEEE &#28014;&#28857;&#31639;&#26415;&#65288; IEC 60559 &#65289;&#65292;</p>
<dl>
<dd>&#23545;&#20110; <code>round</code> &#12289; <code>roundf</code> &#21450; <code>roundl</code> &#20989;&#25968;&#65306;</dd>
</dl>
<ul>
<li>&#24403;&#21069;<a href="c-numeric-fenv-FE_round.html">&#33293;&#20837;&#27169;&#24335;</a>&#26080;&#25928;&#12290;</li>
<li>&#33509; <code>arg</code> &#20026; &plusmn;&infin; &#65292;&#21017;&#36820;&#22238;&#19981;&#20462;&#25913;&#30340;&#35813;&#20540;</li>
<li>&#33509; <code>arg</code> &#20026; &plusmn;0 &#65292;&#21017;&#36820;&#22238;&#19981;&#20462;&#25913;&#30340;&#35813;&#20540;</li>
<li>&#33509; <code>arg</code> &#20026; NaN &#65292;&#21017;&#36820;&#22238; NaN</li>
</ul>
<dl>
<dd>&#23545;&#20110; <code>lround</code> &#19982; <code>llround</code> &#20989;&#25968;&#26063;&#65306;</dd>
</dl>
<ul>
<li>&#20915;&#19981;&#24341;&#21457; <span class="t-lc"><a href="c-numeric-fenv-FE_exceptions.html">FE_INEXACT</a></span></li>
<li>&#24403;&#21069;<a href="c-numeric-fenv-FE_round.html">&#33293;&#20837;&#27169;&#24335;</a>&#26080;&#25928;&#12290;</li>
<li>&#33509; <code>arg</code> &#20026; &plusmn;&infin; &#65292;&#21017;&#24341;&#21457; <span class="t-lc"><a href="c-numeric-fenv-FE_exceptions.html">FE_INVALID</a></span> &#24182;&#36820;&#22238;&#23454;&#29616;&#23450;&#20041;&#20540;</li>
<li>&#33509;&#33293;&#20837;&#32467;&#26524;&#22312;&#36820;&#22238;&#31867;&#22411;&#30340;&#33539;&#22260;&#22806;&#65292;&#21017;&#24341;&#21457; <span class="t-lc"><a href="c-numeric-fenv-FE_exceptions.html">FE_INVALID</a></span> &#24182;&#36820;&#22238;&#23454;&#29616;&#23450;&#20041;&#20540;</li>
<li>&#33509; <code>arg</code> &#20026; NaN &#65292;&#21017;&#24341;&#21457; <span class="t-lc"><a href="c-numeric-fenv-FE_exceptions.html">FE_INVALID</a></span> &#24182;&#36820;&#22238;&#23454;&#29616;&#23450;&#20041;&#20540;</li>
</ul>
<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">&#27880;&#24847;</span></h3>
<p><code>round</code> &#22312;&#33293;&#20837;&#38750;&#25972;&#25968;&#26377;&#38480;&#20540;&#26102;&#65292;&#21487;&#20197;&#65288;&#20294;&#19981;&#35201;&#27714;&#65289;&#24341;&#21457; <span class="t-lc"><a href="c-numeric-fenv-FE_exceptions.html">FE_INEXACT</a></span> &#12290;</p>
<p>&#25152;&#26377;&#26631;&#20934;&#28014;&#28857;&#26684;&#24335;&#20013;&#65292;&#26368;&#22823;&#21487;&#34920;&#31034;&#28014;&#28857;&#20540;&#22343;&#20026;&#20934;&#30830;&#30340;&#25972;&#25968;&#65292;&#25925; <code>round</code> &#33258;&#36523;&#20915;&#19981;&#19978;&#28322;&#65307;&#28982;&#32780;&#22312;&#23384;&#20648;&#20110;&#25972;&#25968;&#23545;&#35937;&#26102;&#65292;&#32467;&#26524;&#21487;&#33021;&#28322;&#20986;&#20219;&#20309;&#25972;&#25968;&#31867;&#22411;&#65288;&#21253;&#21547; <span class="t-lc"><a href="c-types-integer.html">intmax_t</a></span> &#65289;&#12290;</p>
<p><a rel="nofollow" class="external text" href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/lround.html">POSIX &#25351;&#23450;</a> <code>lround</code> &#25110; <code>llround</code> &#24341;&#21457; <span class="t-lc"><a href="c-numeric-fenv-FE_exceptions.html">FE_INEXACT</a></span> &#30340;&#25152;&#26377;&#24773;&#20917;&#37117;&#26159;&#23450;&#20041;&#22495;&#38169;&#35823;&#12290;</p>
<p><code>round</code> &#30340; <span class="t-c"><span class="mw-geshi c source-c"><span class="kw4">double</span></span></span> &#29256;&#26412;&#22914;&#21516;&#23454;&#29616;&#22914;&#19979;&#65306;</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;">
<div class="c source-c">
<pre class="de1"><span class="co2">#include &lt;math.h&gt;</span>
<span class="co2">#include &lt;fenv.h&gt;</span>
<span class="co2">#pragma STDC FENV_ACCESS ON</span>
<span class="kw4">double</span> round<span class="br0">(</span><span class="kw4">double</span> x<span class="br0">)</span>
<span class="br0">{</span>
fenv_t save_env<span class="sy4">;</span>
<a href="c-numeric-fenv-feholdexcept.html"><span class="kw724">feholdexcept</span></a><span class="br0">(</span><span class="sy3">&amp;</span>save_env<span class="br0">)</span><span class="sy4">;</span>
<span class="kw4">double</span> result <span class="sy1">=</span> <a href="c-numeric-math-rint.html"><span class="kw690">rint</span></a><span class="br0">(</span>x<span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">if</span> <span class="br0">(</span><a href="c-numeric-fenv-fetestexcept.html"><span class="kw716">fetestexcept</span></a><span class="br0">(</span><a href="c-numeric-fenv-FE_exceptions.html"><span class="kw728">FE_INEXACT</span></a><span class="br0">)</span><span class="br0">)</span> <span class="br0">{</span>
<a href="c-numeric-fenv-feround.html"><span class="kw721">fesetround</span></a><span class="br0">(</span><a href="c-numeric-fenv-FE_round.html"><span class="kw734">FE_TOWARDZERO</span></a><span class="br0">)</span><span class="sy4">;</span>
result <span class="sy1">=</span> <a href="c-numeric-math-rint.html"><span class="kw690">rint</span></a><span class="br0">(</span><a href="c-numeric-math-copysign.html"><span class="kw700">copysign</span></a><span class="br0">(</span><span class="nu16">0.5</span> <span class="sy2">+</span> <a href="c-numeric-math-fabs.html"><span class="kw644">fabs</span></a><span class="br0">(</span>x<span class="br0">)</span>, x<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span>
<a href="c-numeric-fenv-feupdateenv.html"><span class="kw725">feupdateenv</span></a><span class="br0">(</span><span class="sy3">&amp;</span>save_env<span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">return</span> result<span class="sy4">;</span>
<span class="br0">}</span></pre></div>
</div>
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">&#31034;&#20363;</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 &lt;stdio.h&gt;</span>
<span class="co2">#include &lt;math.h&gt;</span>
<span class="co2">#include &lt;fenv.h&gt;</span>
<span class="co2">#include &lt;limits.h&gt;</span>
<span class="co2">#pragma STDC FENV_ACCESS ON</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="co1">// round</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;round(+2.3) = %+.1f &quot;</span>, round<span class="br0">(</span><span class="nu16">2.3</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;round(+2.5) = %+.1f &quot;</span>, round<span class="br0">(</span><span class="nu16">2.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;round(+2.7) = %+.1f<span class="es1">\n</span>&quot;</span>, round<span class="br0">(</span><span class="nu16">2.7</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;round(-2.3) = %+.1f &quot;</span>, round<span class="br0">(</span><span class="sy2">-</span><span class="nu16">2.3</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;round(-2.5) = %+.1f &quot;</span>, round<span class="br0">(</span><span class="sy2">-</span><span class="nu16">2.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;round(-2.7) = %+.1f<span class="es1">\n</span>&quot;</span>, round<span class="br0">(</span><span class="sy2">-</span><span class="nu16">2.7</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;round(-0.0) = %+.1f<span class="es1">\n</span>&quot;</span>, round<span class="br0">(</span><span class="sy2">-</span><span class="nu16">0.0</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;round(-Inf) = %+f<span class="es1">\n</span>&quot;</span>, round<span class="br0">(</span><span class="sy2">-</span>INFINITY<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<span class="co1">// lround</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;lround(+2.3) = %ld &quot;</span>, lround<span class="br0">(</span><span class="nu16">2.3</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;lround(+2.5) = %ld &quot;</span>, lround<span class="br0">(</span><span class="nu16">2.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;lround(+2.7) = %ld<span class="es1">\n</span>&quot;</span>, lround<span class="br0">(</span><span class="nu16">2.7</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;lround(-2.3) = %ld &quot;</span>, lround<span class="br0">(</span><span class="sy2">-</span><span class="nu16">2.3</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;lround(-2.5) = %ld &quot;</span>, lround<span class="br0">(</span><span class="sy2">-</span><span class="nu16">2.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;lround(-2.7) = %ld<span class="es1">\n</span>&quot;</span>, lround<span class="br0">(</span><span class="sy2">-</span><span class="nu16">2.7</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;lround(-0.0) = %ld<span class="es1">\n</span>&quot;</span>, lround<span class="br0">(</span><span class="sy2">-</span><span class="nu16">0.0</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;lround(-Inf) = %ld<span class="es1">\n</span>&quot;</span>, lround<span class="br0">(</span><span class="sy2">-</span>INFINITY<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span> <span class="co1">// FE_INVALID &#24341;&#21457;</span>
<span class="co1">// &#38169;&#35823;&#22788;&#29702;</span>
<a href="c-numeric-fenv-feclearexcept.html"><span class="kw715">feclearexcept</span></a><span class="br0">(</span><a href="c-numeric-fenv-FE_exceptions.html"><span class="kw726">FE_ALL_EXCEPT</span></a><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">&quot;lround(LONG_MAX+1.5) = %ld<span class="es1">\n</span>&quot;</span>, lround<span class="br0">(</span><a href="c-types-limits.html"><span class="kw365">LONG_MAX</span></a><span class="sy2">+</span><span class="nu16">1.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">if</span><span class="br0">(</span><a href="c-numeric-fenv-fetestexcept.html"><span class="kw716">fetestexcept</span></a><span class="br0">(</span><a href="c-numeric-fenv-FE_exceptions.html"><span class="kw729">FE_INVALID</span></a><span class="br0">)</span><span class="br0">)</span> <a href="c-io-puts.html"><span class="kw833">puts</span></a><span class="br0">(</span><span class="st0">&quot; FE_INVALID was raised&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span></pre></div>
</div>
<p>&#21487;&#33021;&#30340;&#36755;&#20986;&#65306;</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;">
<div class="text source-text">
<pre class="de1">round(+2.3) = +2.0 round(+2.5) = +3.0 round(+2.7) = +3.0
round(-2.3) = -2.0 round(-2.5) = -3.0 round(-2.7) = -3.0
round(-0.0) = -0.0
round(-Inf) = -inf
lround(+2.3) = 2 lround(+2.5) = 3 lround(+2.7) = 3
lround(-2.3) = -2 lround(-2.5) = -3 lround(-2.7) = -3
lround(-0.0) = 0
lround(-Inf) = -9223372036854775808
lround(LONG_MAX+1.5) = -9223372036854775808
FE_INVALID was raised</pre></div>
</div>
</div>
<h3><span class="mw-headline" id=".E5.BC.95.E7.94.A8">&#24341;&#29992;</span></h3>
<div class="t-ref-std-11">
<ul>
<li>C11 &#26631;&#20934;&#65288;ISO/IEC 9899:2011&#65289;&#65306;</li>
</ul>
<dl>
<dd>
<ul>
<li>7.12.9.6 The round functions (p: 253)</li>
</ul>
</dd>
</dl>
<dl>
<dd>
<ul>
<li>7.12.9.7 The lround and llround functions (p: 253)</li>
</ul>
</dd>
</dl>
<dl>
<dd>
<ul>
<li>7.25 Type-generic math &lt;tgmath.h&gt; (p: 373-375)</li>
</ul>
</dd>
</dl>
<dl>
<dd>
<ul>
<li>F.10.6.6 The round functions (p: 527)</li>
</ul>
</dd>
</dl>
<dl>
<dd>
<ul>
<li>F.10.6.7 The lround and llround functions (p: 528)</li>
</ul>
</dd>
</dl>
<div class="t-ref-std-c99">
<ul>
<li>C99 &#26631;&#20934;&#65288;ISO/IEC 9899:1999&#65289;&#65306;</li>
</ul>
<dl>
<dd>
<ul>
<li>7.12.9.6 The round functions (p: 233)</li>
</ul>
</dd>
</dl>
<dl>
<dd>
<ul>
<li>7.12.9.7 The lround and llround functions (p: 234)</li>
</ul>
</dd>
</dl>
<dl>
<dd>
<ul>
<li>7.22 Type-generic math &lt;tgmath.h&gt; (p: 335-337)</li>
</ul>
</dd>
</dl>
<dl>
<dd>
<ul>
<li>F.9.6.6 The round functions (p: 464)</li>
</ul>
</dd>
</dl>
<dl>
<dd>
<ul>
<li>F.9.6.7 The lround and llround functions (p: 464)</li>
</ul>
</dd>
</dl>
</div>
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">&#21442;&#38405;</span></h3>
<table class="t-dsc-begin">
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="c-numeric-math-floor.html"><span class="t-lines"><span>floor</span><span>floorf</span><span>floorl</span></span></a></div>
<div><span class="t-lines"><span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div>
</div>
</td>
<td>&#35745;&#31639;&#19981;&#22823;&#20110;&#32473;&#23450;&#20540;&#30340;&#26368;&#22823;&#25972;&#25968;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="c-numeric-math-ceil.html"><span class="t-lines"><span>ceil</span><span>ceilf</span><span>ceill</span></span></a></div>
<div><span class="t-lines"><span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div>
</div>
</td>
<td>&#35745;&#31639;&#19981;&#23567;&#20110;&#32473;&#23450;&#20540;&#30340;&#26368;&#23567;&#25972;&#25968;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="c-numeric-math-trunc.html"><span class="t-lines"><span>trunc</span><span>truncf</span><span>truncl</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div>
</div>
</td>
<td>&#21462;&#25972;&#21040;&#32477;&#23545;&#20540;&#19981;&#22823;&#20110;&#32473;&#23450;&#20540;&#30340;&#26368;&#25509;&#36817;&#25972;&#25968;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
</tr>
</table>
</div>
</div>
<div class="visualClear"></div>
</div>
</div>
</div>
</body>
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