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<div align="center" class="title">JAVA程序員必讀：基礎篇（4）對象和簡單數據對象</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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<p class="article"><b>對象和簡單數據對象</b></p>
<p class="article"><b>（5）將對象轉換為Strings</b></p>
<p class="article">首先介紹toString方法：</p>
<p class="article"> 經常需要將一個對象轉換為String，因為你需要將它傳遞給方法，而這個方法只接收String數值。前面我們使用reverseIt方法使用了StringBuffer的toString方法來將StringBuffer轉換為String對象。</p>
<p class="article">class ReverseString {</p>
<p class="article"> public static String reverseIt(String source)
{</p>
<p class="article"> int i, len = source.length();</p>
<p class="article"> StringBuffer dest = new StringBuffer(len);</p>
<p class="article"> for (i = (len - 1); i >= 0; i--) {</p>
<p class="article"> dest.append(source.charAt(i));</p>
<p class="article"> }</p>
<p class="article"> return dest.toString();</p>
<p class="article"> }</p>
<p class="article">}</p>
<p class="article">所有的類從對象類繼承了toString，并且在java.lang包的許多類重載了這個方法來提供一個很有意義的方法
</p>
<p class="article"> 下面說說valueOf方法：</p>
<p class="article">簡單起見，String類提供了一個類方法valueOf。你可以使用valueOf來轉換不同類型的變量為String。比如，為了打印pi的數值，你可以這樣來編寫代碼：
</p>
<p class="article">System.out.println(String.valueOf(Math.PI));</p>
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