Comparing integer Arrays in Java. Why does not == work?

Question

I\'m learning Java and just came up with this subtle fact about the language: if I declare two integer Arrays with the same elements and compare them using == t

Answer 1

If you use == operator with Object you are comparing the references, not the values.
If you use == operator with primitive types (int, long, boolean...) you are checking if they have the same values.

int[] a = {1, 2, 3};
int[] b = {1, 2, 3};

System.out.println(a == b); //return false;

System.out.println(a[0] == b[0]); //return true;



String[] a1 = {"Cat", "Dog", "Mouse"};
String[] b2 = {"Cat", "Dog", "Mouse"};

System.out.println(a1 == b1); //return false;

System.out.println(a1[0] == b1[0]); //return false; Because String are Object

You can use the Arrays.equals(array1, array2) method.