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<title>JAVA程序員必讀：基礎篇(5)---類和繼承 ---- |><| 太平洋電腦網 -> 網絡學院* 開發教室</title>
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<div align="center" class="title">JAVA程序員必讀：基礎篇(5)---類和繼承</div>
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<div align="center"><font color="#666666">編譯：ZSC/太平洋網絡學院</font></div>
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<div align="right" class="gray"><a href="mailto:tntst@pconline.com.cn">［責編:爆破手］</a></div>
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<p class="article"> <b> </b><b><span class="article">5.3 執行嵌套類</span></b></p>
<p class="article"> JAVA編程語言可以讓你在另外一個類中定義一個一個類，即嵌套類。內部的內就是典型的嵌套類。</p>
<p class="article"> JAVA可以讓你定義一個類作為另外一個類的成員，比如： </p>
<p class="article">class EnclosingClass{</p>
<p class="article"> . . .</p>
<p class="article"> class ANestedClass {</p>
<p class="article"> . . .</p>
<p class="article"> }</p>
<p class="article">}</p>
<p class="article"> 你可以使用嵌套類來放映并且強制兩個類之間的關系。當嵌套類只有在嵌入以后才有意義的時候或者當它依靠于嵌入類的函數的實話，你應該在另外一個類定義一個類，即使用嵌套類。比如，文本鼠標只有在特定文本組件中的時候才有意義。
</p>
<p class="article"> 作為圈入類的一個成員，嵌套類有一個特權：它可以毫無限制地訪問圈入類地成員，即使它們定義為private。但是這個特權不是真正特殊的，它跟private以及其它訪問指示是一致的。訪問指示限制了對圈入類外部成員的訪問。嵌套類是處在圈入類中的，這樣它就可以訪問圈入類的成員。
</p>
<p class="article"> 象其它成員一樣，嵌套類可以聲明為static。一個static嵌套類稱為static嵌套類。非static嵌套類稱為內部類。下面給出例子：
</p>
<p class="article">class EnclosingClass{</p>
<p class="article"> . . .</p>
<p class="article"> static class AStaticNestedClass {</p>
<p class="article"> . . .</p>
<p class="article"> }</p>
<p class="article"> class InnerClass {</p>
<p class="article"> . . .</p>
<p class="article"> }</p>
<p class="article">}</p>
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