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<title>std::basic_ios&lt;CharT,Traits&gt;::clear</title>
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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::basic_ios&lt;CharT,Traits&gt;::</span>clear</h1>
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<div id="contentSub"><span class="subpages">&lt; <a href="cpp.html">cpp</a>&lrm; | <a href="cpp-io.html">io</a>&lrm; | <a href="cpp-io-basic_ios.html">basic ios</a></span></div>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">void</span> clear<span class="br0">(</span> <a href="cpp-io-ios_base-iostate.html"><span class="kw1697">std::<span class="me2">ios_base</span><span class="sy4">::</span><span class="me2">iostate</span></span></a> state <span class="sy1">=</span> <a href="cpp-io-ios_base-iostate.html"><span class="kw1698">std::<span class="me2">ios_base</span><span class="sy4">::</span><span class="me2">goodbit</span></span></a> <span class="br0">)</span><span class="sy4">;</span></span></div>
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<p>&#36890;&#36807;&#20197; <code>state</code> &#30340;&#20540;&#36171;&#20540;&#65292;&#35774;&#32622;&#27969;&#38169;&#35823;&#29366;&#24577;&#26631;&#24535;&#12290;&#40664;&#35748;&#36171;&#20540; <span class="t-lc"><a href="cpp-io-ios_base-iostate.html">std::ios_base::goodbit</a></span> &#65292;&#23427;&#25317;&#26377;&#30340;&#25928;&#26524;&#20026;&#28165;&#38500;&#25152;&#26377;&#38169;&#35823;&#29366;&#24577;&#26631;&#24535;&#12290;</p>
<p>&#33509; <span class="t-lc"><a href="cpp-io-basic_ios-rdbuf.html">rdbuf()</a></span> &#20026;&#31354;&#25351;&#38024;&#65288;&#21363;&#26080;&#20851;&#32852;&#30340;&#27969;&#32531;&#20914;&#65289;&#65292;&#21017;&#36171;&#20540; <span class="t-c"><span class="mw-geshi cpp source-cpp">state <span class="sy3">|</span> badbit</span></span> &#12290;&#21487;&#33021;&#25243;&#20986;&#24322;&#24120;&#12290;</p>
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<td>state</td>
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<td>&#26032;&#30340;&#38169;&#35823;&#29366;&#24577;&#26631;&#24535;&#35774;&#32622;&#12290;&#23427;&#33021;&#20026;&#19979;&#21015;&#24120;&#37327;&#30340;&#32452;&#21512;&#65306;
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<td>&#24120;&#37327;</td>
<td>&#35299;&#37322;</td>
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<td><a href="cpp-io-ios_base-iostate.html"><tt>goodbit</tt></a></td>
<td>&#26080;&#38169;&#35823;</td>
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<td><a href="cpp-io-ios_base-iostate.html"><tt>badbit</tt></a></td>
<td>&#19981;&#21487;&#24674;&#22797;&#30340;&#27969;&#38169;&#35823;</td>
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<td><a href="cpp-io-ios_base-iostate.html"><tt>failbit</tt></a></td>
<td>&#36755;&#20837;/&#36755;&#20986;&#25805;&#20316;&#22833;&#36133;&#65288;&#26684;&#24335;&#21270;&#25110;&#25552;&#21462;&#38169;&#35823;&#65289;</td>
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<td><a href="cpp-io-ios_base-iostate.html"><tt>eofbit</tt></a></td>
<td>&#20851;&#32852;&#30340;&#36755;&#20986;&#24207;&#21015;&#24050;&#25269;&#36798;&#25991;&#20214;&#23614;</td>
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<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">&#36820;&#22238;&#20540;</span></h3>
<p>&#65288;&#26080;&#65289;</p>
<h3><span class="mw-headline" id=".E5.BC.82.E5.B8.B8">&#24322;&#24120;</span></h3>
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<td class="mbox-text" style="">&#26412;&#33410;&#26410;&#23436;&#25104;<br />
&#21407;&#22240;&#65306;&#20063;&#38142;&#25509;&#21040; basic_ios::exceptions</td>
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<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">&#31034;&#20363;</span></h3>
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<p>&#26080;&#21442;&#25968;&#30340; clear() &#33021;&#29992;&#20110;&#22312;&#19981;&#26399;&#24453;&#30340;&#36755;&#20837;&#21518;&#21453;&#35774;&#32622; failbit</p>
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<pre class="de1"><span class="co2">#include &lt;iostream&gt;</span>
<span class="co2">#include &lt;string&gt;</span>
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
<span class="kw4">double</span> n<span class="sy4">;</span>
<span class="kw1">while</span><span class="br0">(</span> <a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> <span class="st0">&quot;Please, enter a number<span class="es1">\n</span>&quot;</span>
<span class="sy3">&amp;&amp;</span> <span class="sy3">!</span> <span class="br0">(</span><a href="cpp-io-cin.html"><span class="kw1756">std::<span class="me2">cin</span></span></a> <span class="sy1">&gt;&gt;</span> n<span class="br0">)</span> <span class="br0">)</span>
<span class="br0">{</span>
<a href="cpp-io-cin.html"><span class="kw1756">std::<span class="me2">cin</span></span></a>.<span class="me1">clear</span><span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span>
<a href="cpp-string-basic_string.html"><span class="kw1230">std::<span class="me2">string</span></span></a> line<span class="sy4">;</span>
<a href="cpp-string-basic_string-getline.html"><span class="kw1256">std::<span class="me2">getline</span></span></a><span class="br0">(</span><a href="cpp-io-cin.html"><span class="kw1756">std::<span class="me2">cin</span></span></a>, line<span class="br0">)</span><span class="sy4">;</span>
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> <span class="st0">&quot;I am sorry, but &#39;&quot;</span> <span class="sy1">&lt;&lt;</span> line <span class="sy1">&lt;&lt;</span> <span class="st0">&quot;&#39; is not a number<span class="es1">\n</span>&quot;</span><span class="sy4">;</span>
<span class="br0">}</span>
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> <span class="st0">&quot;Thank you for entering the number &quot;</span> <span class="sy1">&lt;&lt;</span> n <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><span class="sy4">;</span>
<span class="br0">}</span></pre></div>
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<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">&#21442;&#38405;</span></h3>
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<div><a href="cpp-io-basic_ios-setstate.html"><span class="t-lines"><span>setstate</span></span></a></div>
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<td>&#35774;&#32622;&#29366;&#24577;&#26631;&#24535;<br />
<span class="t-mark">(&#20844;&#24320;&#25104;&#21592;&#20989;&#25968;)</span></td>
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<div><a href="cpp-io-basic_ios-rdstate.html"><span class="t-lines"><span>rdstate</span></span></a></div>
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<td>&#36820;&#22238;&#29366;&#24577;&#26631;&#24535;<br />
<span class="t-mark">(&#20844;&#24320;&#25104;&#21592;&#20989;&#25968;)</span></td>
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