Java Arrays deepEquals() method example

public static boolean deepEquals(Object[] a1, Object[] a2)

The deepEquals() method returns true if the two arrays are equal otherwise false.

Requires Java 1.5 and up

Below is a java code demonstrates the use of deepEquals(Object[] a1, Object[] a2) method of Arrays class. The example presented might be simple however it shows the behaviour of the deepEquals() method.

package com.javatutorialhq.java.examples;

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

/*
 * A java example source code to demonstrate
 * the use of deepEquals() method of Arrays class
 */

public class ArraysDeepEqualsExample {

	public static void main(String[] args) {

		// initialize a new String array
		String[] names = new String[]{
			"Alfred","Beth","Stan"	
		};
		
		Object[] data = new Object[3];
		data[0] = "Alfred";
		data[1] = "Beth";
		data[2] = "Stan";
		
		System.out.println("******One dimensional array******");
		// test for equality		
		boolean result = Arrays.equals(names, data);
		if(result){
			System.out.println("They are equals");
		}
		else{
			System.out.println("They are not equals");
		}
		
		System.out.println("******Multi dimensional array******");
		
		// test multi dimensional array
		
		int[][] value1 = new int[2][2];
		int[][] value2 = new int[2][2];
		
		value1[0][0] = 1;
		value1[0][1] = 2;
		value1[1][0] = 3;
		value1[1][1] = 4;
		
		
		value2[0][0] = 1;
		value2[0][1] = 2;
		value2[1][0] = 3;
		value2[1][1] = 4;
	
		// check equality using equals
		// value1 and value2 values are equals and should result to true
		result = Arrays.equals(value1,value2);
		if(result){
			System.out.println("Test OK using equals");
		}
		else
			System.out.println("Test Fails using equals");
		
		
		// check equality properly
		// value1 and value2 values are equals and should result to true
		result = Arrays.deepEquals(value1,value2);
		if(result){
			System.out.println("Test OK using deepequals");
		}
		else
			System.out.println("Test Fails using deepequals");
		
		
	}
}

The above java example source code demonstrates the use of deepEquals() method of Arrays class. Example above show the difference in using equals and deepEquals. As you can see using equals works fine in single dimensional array but it will fail if we are testing multi dimensional array. To properly handle the equality test of multi dimensional array, the deepEquals method works like a charm.

Below is the sample output when you run the above example.

• Java Arrays Class Tutorial
• Java Tutorial

• Oracle Java Documentation