Java列表去重

「爱情、让人受尽委屈。」 2024-03-16 18:23 56阅读 0赞

## **问题** ##

很多时候我们需要对列表进行去重处理，咋整呢？

## **方法** ##

采用TreeSet方法

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 <td>import java.lang.reflect.Method; import java.util.ArrayList; import java.util.List; import java.util.TreeSet; public class ListQuChong01 { &nbsp; &nbsp;public static void main(String[] args) { &nbsp; &nbsp; &nbsp; &nbsp;List&lt;Integer&gt; list = new ArrayList&lt;&gt;(){ { &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;add(1); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;add(3); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;add(3); &nbsp; &nbsp; &nbsp; &nbsp;}}; &nbsp; &nbsp; &nbsp; &nbsp;System.out.println("原列表数："+ list); &nbsp; &nbsp; &nbsp; &nbsp;method(list); &nbsp; &nbsp;} &nbsp; &nbsp;public static void method(List&lt;Integer&gt; list){ &nbsp; &nbsp; &nbsp; &nbsp;TreeSet&lt;Integer&gt; set = new TreeSet&lt;&gt;(list); &nbsp; &nbsp; &nbsp; &nbsp;System.out.println("结果："+set); &nbsp; &nbsp;} }</td> 
 </tr> 
 </tbody> 
</table>

采用迭代方法

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 <td>import java.lang.reflect.Method; import java.util.ArrayList; import java.util.Iterator; import java.util.List; public class ListQuChong02 { &nbsp; &nbsp;public static void main(String[] args) { &nbsp; &nbsp; &nbsp; &nbsp;List&lt;Integer&gt; yuan = new ArrayList&lt;&gt;(){ { &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;add(2); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;add(3); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;add(3); &nbsp; &nbsp; &nbsp; &nbsp;}}; &nbsp; &nbsp; &nbsp; &nbsp;System.out.println("原列表："+yuan); &nbsp; &nbsp; &nbsp; &nbsp;Method(yuan); &nbsp; &nbsp;} &nbsp; &nbsp;public static void Method(List&lt;Integer&gt; yuan) { &nbsp; &nbsp; &nbsp; &nbsp;Iterator&lt;Integer&gt; iterator = yuan.listIterator(); &nbsp; &nbsp; &nbsp; &nbsp;while (iterator.hasNext()){ &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Integer i = iterator.next(); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;if (yuan.indexOf(i) != yuan.lastIndexOf(i)) { &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;iterator.remove(); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;} &nbsp; &nbsp; &nbsp; &nbsp;} &nbsp; &nbsp; &nbsp; &nbsp;System.out.println("结果："+ yuan); &nbsp; &nbsp;} }</td> 
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 </tbody> 
</table>

## **结语** ##

针对列表去重问题，提出两种方法，分别是TreeSet和迭代，通过实验，证明该方法是有效的，还有很多方法能解决，本文仅提供两种方法，未来可以继续总结。