What will be the output of the following code?

class Super { static String ID = "QBANK"; }
class Sub extends Super{
  static { System.out.print("In Sub"); }
}
class Test{
  public static void main(String[] args) {
    System.out.println(Sub.ID);
  }
}
Explanation
A static block will be executed only during the class initialization.
A class does not need to be initialized, in order to access static fields of a parent class.
In order to initialize a class one of the following should happen:
1. A class instance or an array of class type is created.
2. A read or a write operation on a non-constant field of the same class (i. e. not inherited) is performed.
3. A method implemented in the same class (i. e. not inherited) should be invoked (including main method).
Since the Sub class has access to the ID variable (via inheritance) - the string "QBANK" will be printed, with no issues.
Since initialization of Sub class does not happen - the static block is not executed and the "In Sub" string will not be printed.

Follow CodeGalaxy

Mobile Beta

Get it on Google Play
Send Feedback
Cosmo
Sign Up Now
or Subscribe for future quizzes