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Java数组去除重复元素的最佳实践是什么？

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后端开发
2025-10-13
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在Java中,去除数组中的重复元素是一个常见的需求，这可以通过多种方法实现，以下是一些常用的方法：

使用HashSet

HashSet是一个不允许重复元素的集合,因此可以将数组中的元素添加到HashSet中，HashSet会自动去除重复的元素，将HashSet中的元素重新放入数组中。

Java数组去除重复元素的最佳实践是什么？第1张

使用ArrayList

ArrayList允许重复元素,但是可以通过遍历ArrayList，检查每个元素是否已经存在于ArrayList中，如果不存在，则添加到ArrayList中。

import java.util.ArrayList; import java.util.Arrays; public class Main { public static void main(String[] args) { Integer[] array = {1, 2, 3, 4, 5, 3, 2, 1, 6, 7, 8, 7, 9, 10, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128}; ArrayList<Integer> list = new ArrayList<>(); for (Integer i : array) { if (!list.contains(i)) { list.add(i); } } Integer[] newArray = list.toArray(new Integer[0]); System.out.println(Arrays.toString(newArray)); } }

使用LinkedHashSet

LinkedHashSet是一个有序的集合,它允许重复元素，但是每个元素只会出现一次，这可以通过将数组中的元素添加到LinkedHashSet中实现。

Java数组去除重复元素的最佳实践是什么？第2张

import java.util.LinkedHashSet; import java.util.Arrays; public class Main { public static void main(String[] args) { Integer[] array = {1, 2, 3, 4, 5, 3, 2, 1, 6, 7, 8, 7, 9, 10, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128}; LinkedHashSet<Integer> set = new LinkedHashSet<>(); for (Integer i : array) { set.add(i); } Integer[] newArray = set.toArray(new Integer[0]); System.out.println(Arrays.toString(newArray)); } }

使用排序和双指针

对于整数数组,可以先对数组进行排序，然后使用两个指针遍历数组，去除重复的元素。

Java数组去除重复元素的最佳实践是什么？第3张

import java.util.Arrays; public class Main { public static void main(String[] args) { Integer[] array = {1, 2, 3, 4, 5, 3, 2, 1, 6, 7, 8, 7, 9, 10, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128}; Arrays.sort(array); Integer[] newArray = new Integer[array.length]; int j = 0; for (int i = 0; i < array.length 1; i++) { if (array[i] != array[i + 1]) { newArray[j++] = array[i]; } } newArray[j++] = array[array.length 1]; System.out.println(Arrays.toString(newArray)); } }