Why are these == but not `equals()`?

Question

I\'m a bit confused about the way Java treats == and equals() when it comes to int, Integer and other types of numbers.

Answer 1

Java will convert an Integer into an int automatically, if needed. Same applies to Short. This feature is called autoboxing and autounboxing. You can read about it here.

It means that when you run the code:

int a = 5;
Integer b = a;
System.out.println(a == b);

Java converts it into:

int a = 5;
Integer b = new Integer(a);
System.out.println(a == b.valueOf());