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<title>JAVA程序員必讀：基礎篇(7)---編程中的一些共同的問題 ---- |><| 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(7)---編程中的一些共同的問題</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>問題三：程序不能工作？究竟出了什么錯誤？</b></p>
<p class="article">以下是JAVA新手犯的公共錯誤，注意以下的各條：</p>
<ol>
<p>
<li class="article">你是否忘記在在switch語句中的每一個case語句使用break？</li>
<p></p>
<p>
<li class="article">你是否在應該使用比較運算符號==的時候使用了賦值運算符=？</li>
<p></p>
<p>
<li class="article">在循環語句中的終止條件是否正確？確保你沒有過早或者過遲終止循環。也就是說，確保正確使用<
或<=或 >或 >= a運算符。</li>
<p></p>
<p>
<li class="article">記住數組的索引是從0開始的，因此數組的循環應該是： </li>
<p></p>
<p class="article"> for (int i = 0; i < array.length; i++)</p>
<p class="article"> . . .</p>
<p>
<li class="article">你是否在比較浮點型數使用了==？大于號和小于號（>和<）運算符在對浮點數的條件邏輯中更合適。</li>
<p></p>
<p>
<li class="article">你是否對封裝、繼承或者其它面向對象編程和設計概念理解有問題？</li>
<p></p>
<p>
<li class="article">確保語句塊圈在大括號{和}中間。下面的代碼塊看起來好象是對的，因為它采用縮進的編寫，但是你仔細看這里缺少了{
}：</li>
<p></p>
<p class="article"> for (int i = 0; i < arrayOfInts.length; i++)</p>
<p class="article"> arrayOfInts[i] = i;</p>
<p class="article"> System.out.println("[i] = " + arrayOfInts[i]);</p>
<p>
<li class="article">你是否正確使用條件運算符號？要確保理解&& 和 ||以及正確使用它們。</li>
<p></p>
<p>
<li class="article">你是否使用了否定運算符（!）？盡量不要使用它。這樣會減少錯誤的發生。</li>
<p></p>
<p>
<li class="article">你是否使用了do-while語句。如果有，你知道do-while語句至少執行一次嗎？它跟while循環語句不一樣的，它可以連一次都不執行。</li>
<p></p>
<p>
<li class="article">你是否想從方法中改變參數的數值？在JAVA中的參數是由參數來傳遞的，它不能在方法中改變。</li>
<p></p>
<p>
<li class="article">你是否無意地增加一個分號（;）來過早終止語句？比如： </li>
<p></p>
</ol>
<p class="article"> for (int i = 0; i < arrayOfInts.length; i++)
;</p>
<p class="article"> arrayOfInts[i] = i</p>
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