Execution of Java static blocks in subclasses

Question

I am preparing myself for Java certification test and I have found an interesting question related to the execution of Java static blocks. I have spent a lot of time reading

Answer 1

In this case, Child.age is equivalent to Parent.age. JRE will treat it as Parent.age, that's why only Parent is statically initialized, and Child's static initializer is skipped.

Answer 2

You saw that Child class was loaded, but it wasn't initialized.

Accessing Child.age doesn't cause the initialization of the Child class, since age is a member of Parent class. Therefore only Parent class is initialized, and age remains 0.

12.4.1. When Initialization Occurs

A class or interface type T will be initialized immediately before the first occurrence of any one of the following:

• T is a class and an instance of T is created.

• A static method declared by T is invoked.

• A static field declared by T is assigned.

• A static field declared by T is used and the field is not a constant variable (§4.12.4).

• T is a top level class (§7.6) and an assert statement (§14.10) lexically nested within T (§8.1.3) is executed.

In your case you accessed a static field declared by Parent, so only Parent is initialized.