Boxed Primitives and Equivalence

Question

So I was asked this question today.

Integer a = 3;
Integer b = 2;
Integer c = 5;
Integer d = a + b;
System.out.println(c == d);

What will t

Answer 1

Caching happens outside of autoboxing too, consider this:

Integer a = 1;
Integer b = new Integer(1);
Integer c = Integer.valueOf(1);

System.out.println(a == b);
System.out.println(b == c);
System.out.println(c == a);

this will print:

false
false
true

So I guess that generally you want to stay away from '==' when comparing Objects