Java 实例以下实例演示了如何使用 retainAll () 方法来计算两个数组的交集：
Main.java 文件
import java.util.ArrayList; public class Main { 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("array1 数组元素："+objArray); System.out.println("array2 数组元素："+objArray2); objArray.retainAll(objArray2); System.out.println("array2 & array1 数组交集为："+objArray); }}
以上代码运行输出结果为：
array1 数组元素：[common1, common2, notcommon2]array2 数组元素：[common1, common2, notcommon, notcommon1]array2 & array1 数组交集为：[common1, common2]