Question

I know that static blocks are run before anything. But here, what happens when B.test() is called? Order of execution and setting of values? Later, when b1 is set to null, still how b1.i evaluates to 20?

class  B
{    
     static int i;
     static {
         i = 20;
         System.out.println("SIB");
     }
     static int test() {  
         int i = 24;
         System.out.println(i);
         return i; 
     }
}

public class Manager {
    public static void main(String[] arg) {
         B.test();
         B b1 = null;
         System.out.println(b1.i);  
    }
}

The output is:

SIB
24
20

Answer 1

i is static, so b1.i is equivalent to B.i. Just setting b1 to null doesn’t change any static variables.

When B.test() is called, first the B class is loaded, and the static blocks are run. Next, B.test() creates a new method-local variable called i, which is completely different from B.i. This new, local i is printed and returned. No changes are made to B.i, and certainly not just because you created a new B object reference that was null — that would never have any effect on anything.