java list去重

1.不带类型写法：

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List listWithoutDup = new ArrayList(new HashSet(listWithDup));

2.带类型写法（以String类型为例）：
1)Java 7以下写法：

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List<string> listWithoutDup = new ArrayList<string>(new HashSet<string>(listWithDup));</string></string></string>

2)Java 7及以上写法：

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List<string> listWithoutDup = new ArrayList<>(new HashSet<>(listWithDup));</string>


样例：

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import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
 
public class Test {
    public static void main(String[] args) {
        List<string> listWithDup = new ArrayList<string>();
        listWithDup.add("1");
        listWithDup.add("2");
        listWithDup.add("3");
        listWithDup.add("1");
 
        List<string> listWithoutDup = new ArrayList<string>(new HashSet<string>(listWithDup));
        System.out.println("list with dup:"+ listWithDup);
        System.out.println("list without dup:"+ listWithoutDup);
    }
}</string></string></string></string></string>

样例运行结果： list with dup:[1, 2, 3, 1]
list without dup:[3, 2, 1]

That which didn't kill me makes me stronger
posted @ 2017-01-07 12:14  datasyman  阅读(361)  评论(0)  编辑  收藏  举报