如何查找從數組中的公共元素？

解決方法

下麵的示例演示如何找到從兩個數組公共元素，並將它們存儲在數組中。

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("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);
   }
}

結果

上麵的代碼示例將產生以下結果。

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]