Java Program to check if two arrays are Equal

1. Using Custom Method

First we will write the manual method to compare two Java Arrays for Equality. The logic is pretty simple, first we compare the length of both Arrays in consideration and if that is equal we go on comparing all the elements.

    public static void main(String args[]) {
        int[] myFirstArray = { 12, 42, 34, 19 };
        int[] mySecondArray = { 12, 42, 34, 19 };
        int[] myThirdArray = { 12, 42, 33, 19 };

        if (checkEqual(myFirstArray, mySecondArray)) {
            System.out.println("Array are equal");
        } else {
            System.out.println("Array not equal");
        }

        if (checkEqual(myFirstArray, myThirdArray)) {
            System.out.println("Array are equal");
        } else {
            System.out.println("Array not equal");
        }

    }

    // Custom Method
    public static boolean checkEqual(int[] array1, int[] array2) {
        // Check length
        if (array1.length != array2.length) {
            return false;
        } else {
            for (int i = 0; i < array1.length; i++) {
                if (array1[i] != array2[i])
                    return false;
            }
        }

        return true;
    }

}

2. Using equals() method of java.util.Arrays library

The similar can be achieved with equals() method from java.util.Arrays library. You can pass any two array of same data type and the method will true if the arrays are equal and false for non equality.

public class ArrayEqual {

    public static void main(String args[]) {
        int[] myFirstArray = { 12, 42, 34, 19 };
        int[] mySecondArray = { 12, 42, 34, 19 };
        int[] myThirdArray = { 12, 42, 33, 19 };

        System.out.println(Arrays.equals(myFirstArray, mySecondArray));
        System.out.println(Arrays.equals(myFirstArray, myThirdArray));

    }
}