Check if ArrayList contains an Array Object

Question

Is there a way to check if an ArrayList contains an array of objects? For example I have an arrayList

ArrayList<Integer[]> myList = new ArrayList<Integer[]>();
mylist.add(new Integer[]{5,5});
mylist.add(new Integer[]{1,1});

I would like to check if it contains a specific Integer array. Like:

Integer[] myArray = new Integer[]{5,5};

if I use the myList.containts(myArray); it should return true, but it checks if the Integer object is containted, not the array Values.

Is there a way to check the values?

You'll have to do it on your own, values cannot be assessed like this. — Darshan Lila
– Darshan Lila, Commented Jul 12, 2014 at 13:03

Patricia Shanahan · Accepted Answer · 2014-07-12 13:05:20Z

java.util.Arrays contains several array-related utility methods, including Arrays.deepEquals(Object[] a1, Object[] a2). You can scan the list looking for any element that is equal to new Integer[]{5,5} according to that test:

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class Test {
  public static void main(String[] args) {
    ArrayList<Integer[]> myList = new ArrayList<Integer[]>();
    myList.add(new Integer[] { 5, 5 });
    myList.add(new Integer[] { 1, 1 });
    System.out.println(deepContains(myList, new Integer[] { 5, 5 }));
    System.out.println(deepContains(myList, new Integer[] { 5, 3 }));
  }

  public static boolean deepContains(List<Integer[]> list, Integer[] probe) {
    for (Integer[] element : list) {
      if (Arrays.deepEquals(element, probe)) {
        return true;
      }
    }
    return false;
  }
}

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