Example: ArrayEqualityArraysEquals in Java

// ArrayEqualityArraysEquals
import java.util.Arrays;

public class Main {
    public static void main(String[] args) {
        // Primitive arrays (e.g., int[])
        int[] arrP1 = {1, 2, 3};
        int[] arrP2 = {1, 2, 3};
        int[] arrP3 = {1, 3, 2};
        int[] arrP4 = {1, 2};

        System.out.println("--- Primitive Array Examples (int[]) ---");
        System.out.println("arrP1 and arrP2 equal: " + Arrays.equals(arrP1, arrP2));
        System.out.println("arrP1 and arrP3 equal: " + Arrays.equals(arrP1, arrP3));
        System.out.println("arrP1 and arrP4 equal: " + Arrays.equals(arrP1, arrP4));

        // Object arrays (e.g., String[])
        String[] arrS1 = {"apple", "banana", "cherry"};
        String[] arrS2 = {"apple", "banana", "cherry"};
        String[] arrS3 = {"apple", "orange", "cherry"};
        String[] arrS4 = {"apple", "banana"};
        String[] arrS5 = {"apple", null, "cherry"};
        String[] arrS6 = {"apple", null, "cherry"};

        System.out.println("\n--- Object Array Examples (String[]) ---");
        System.out.println("arrS1 and arrS2 equal: " + Arrays.equals(arrS1, arrS2));
        System.out.println("arrS1 and arrS3 equal: " + Arrays.equals(arrS1, arrS3));
        System.out.println("arrS1 and arrS4 equal: " + Arrays.equals(arrS1, arrS4));
        System.out.println("arrS5 and arrS6 equal: " + Arrays.equals(arrS5, arrS6)); // Handles null elements correctly

        // Arrays with null references
        int[] nullArr1 = null;
        int[] nullArr2 = null;
        int[] nonNullArr = {1, 2};

        System.out.println("\n--- Null Array Examples ---");
        System.out.println("nullArr1 and nullArr2 equal: " + Arrays.equals(nullArr1, nullArr2));
        System.out.println("nullArr1 and nonNullArr equal: " + Arrays.equals(nullArr1, nonNullArr));

        // For multi-dimensional arrays, Arrays.equals() does a shallow comparison
        // It compares the references of the inner arrays, not their content.
        // For deep comparison of multi-dimensional arrays, use Arrays.deepEquals().
        int[][] multiArr1 = {{1, 2}, {3, 4}};
        int[][] multiArr2 = {{1, 2}, {3, 4}};
        int[][] multiArr3 = {{1, 2}, {3, 5}};

        System.out.println("\n--- Multi-dimensional Array Note ---");
        System.out.println("multiArr1 and multiArr2 (shallow) equal: " + Arrays.equals(multiArr1, multiArr2)); // This will be false!
        System.out.println("multiArr1 and multiArr2 (deep) equal: " + Arrays.deepEquals(multiArr1, multiArr2));
        System.out.println("multiArr1 and multiArr3 (deep) equal: " + Arrays.deepEquals(multiArr1, multiArr3));
    }
}