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3.10.2 枚举类型的排列</div>
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枚举元素的排列可以使用下列的语法自动指定。 </p>
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<strong>表格 3-3：枚举元素的排列</strong> </p><div class="Element63">
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<i>name</i> </div></td><td class="Element67" valign="top" width="80%">
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将下一个连续的数与<i>name</i>关联起来 </div></td></tr><tr>
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<i>name</i> <span style="color: #800080">=</span> <i>C</i> </div></td><td class="Element67" valign="top" width="80%">
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将常量<i>C</i>与<i>name</i>关联起来 </div></td></tr><tr>
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<i>name<span style="color: #800080"></i>[<i></span>N<span style="color: #800080"></i>]</span> </div></td><td class="Element67" valign="top" width="80%">
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以下列顺序产生N个命名的常量：<i>name0</i>、<i>name1</i>、…、<i>nameN-1</i>。<i>N</i>必须是一个integral常量。 </div></td></tr><tr>
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<i>name<span style="color: #800080"></i>[<i></span>N<span style="color: #800080"></i>]</span> <span style="color: #800080">=</span> <i>C</i> </div></td><td class="Element67" valign="top" width="80%">
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可选地，一个常量可以被赋值到产生的命名常量以便将常量与第一个产生的命名常量关联起来。后续产生的命名常量与连续的值相关联。<i>N</i>必须是一个integral常量。 </div></td></tr><tr>
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<i>name<span style="color: #800080"></i>[<i></span>N<span style="color: #800080"></i>:<i></span>M<span style="color: #800080"></i>]</span> </div></td><td class="Element67" valign="top" width="80%">
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产生一系列的命名常量，它起始于<i>nameN</i>，然后递增或递减直到到达命名常量<i>nameM</i>。 </div></td></tr><tr>
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<i>name<span style="color: #800080"></i>[<i></span>N<span style="color: #800080"></i>:<i></span>M<span style="color: #800080"></i>]</span> <span style="color: #800080">=</span> <i>C</i> </div></td><td class="Element67" valign="top" width="80%">
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可选地，一个常量可以被赋值到产生的命名常量以便将常量与第一个产生的命名常量关联起来。后续产生的命名常量与连续的值相关联。<i>N</i>和<i>M</i>必须是一个integral常量。 </div></td></tr></table></div></div>
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例如： </p><div class="Element170">
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<div class="Element13"><div class="Element12" id="code00060"><pre class="Element12"><span style="color: #0000FF">typedef enum</span> <span style="color: #800080">{</span>add<span style="color: #800080">=</span><span style="color: #FF0000">10</span><span style="color: #800080">,</span> sub<span style="color: #800080">[</span><span style="color: #FF0000">5</span><span style="color: #800080">],</span> jmp<span style="color: #800080">[</span><span style="color: #FF0000">6</span><span style="color: #800080">:</span><span style="color: #FF0000">8</span><span style="color: #800080">]}</span> E1<span style="color: #800080">;</span></pre></div></div>
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在这个例子中定义了一个枚举类型<i>E1</i>，它将<span style="color: #FF0000">10</span>赋值给枚举命名常量<i>add</i>。它还产生了枚举命名常量<i>sub0</i>、<i>sub1</i>、<i>sub2</i>、<i>sub3</i>、<i>sub4</i>，并将它们分别赋值为<span style="color: #FF0000">11…15</span>。最后，这个例子还产生了枚举命名常量<i>jmp6</i>、<i>jmp7</i>和<i>jmp8</i>，并分别赋值为<span style="color: #FF0000">16</span> – <span style="color: #FF0000">18</span>。 </p><div class="Element170">
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<div class="Element13"><div class="Element12" id="code00061"><pre class="Element12"><span style="color: #0000FF">enum</span> <span style="color: #800080">{</span>register<span style="color: #800080">[</span><span style="color: #FF0000">2</span><span style="color: #800080">]=</span><span style="color: #FF0000">1</span><span style="color: #800080">, </span>register<span style="color: #800080">[</span><span style="color: #FF0000">2</span><span style="color: #800080">:</span><span style="color: #FF0000">4</span><span style="color: #800080">]=</span><span style="color: #FF0000">10</span><span style="color: #800080">}</span> vr<span style="color: #800080">;</span></pre></div></div>
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上面的例子声明了枚举变量<i>vr</i>，它产生了枚举命名常量<i>register0</i>和<i>register1</i>，并分别赋值为<span style="color: #FF0000">1</span>和<span style="color: #FF0000">2</span>。然后，它产生了枚举命名常量<i>register2</i>、<i>register3</i>和<i>register4</i>，并分别赋值为<span style="color: #FF0000">10</span>、<span style="color: #FF0000">11</span>和<span style="color: #FF0000">12</span>。</p></div>
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