Java如何从数组中查找公共的元素？

在Java中，如何从数组中查找公共的元素？

示例

以下示例显示了如何从两个数组中查找公共元素并将其存储在数组中。

package com.yiibai;

import java.util.*;

public class FindCommonElements {
    public static void main(String[] args) {
        ArrayList objArray = new ArrayList();
        ArrayList objArray2 = new ArrayList();
        objArray2.add(0, "common1");
        objArray2.add(1, "common2");
        objArray2.add(2, "notcommon");
        objArray2.add(3, "notcommon1");
        objArray.add(0, "common1");
        objArray.add(1, "common2");
        objArray.add(2, "notcommon2");
        System.out.println("Array elements of array1" + objArray);
        System.out.println("Array elements of array2" + objArray2);
        objArray.retainAll(objArray2);
        System.out
                .println("Array1 after retaining common elements of array2 & array1"
                        + objArray);
    }
}

执行上面示例代码，得到以下结果 -

Array elements of array1[common1, common2, notcommon2]
Array elements of array2[common1, common2, notcommon, notcommon1]
Array1 after retaining common elements of array2 & array1[common1, common2]

示例2

从数组中查找出现另一个数组中的公共元素的示例。

package com.yiibai;

public class FindCommonElements2 {
    public static void main(String a[]) {
        int[] arr1 = { 14, 17, 13, 19, 12 };
        int[] arr2 = { 13, 12, 112, 19, 400, 32, 14 };

        for (int i = 0; i < arr1.length; i++) {
            for (int j = 0; j < arr2.length; j++) {
                if (arr1[i] == arr2[j]) {
                    System.out.println(arr1[i]);
                }
            }
        }
    }
}

执行上面示例代码，得到以下结果 -