Initialization Blocks : variable scope « Java Source And Data Type « SCJP

1. SCJP
2. Java Source And Data Type
3. variable scope

Init blocks execute in the order they appear.
Static init blocks run once, when the class is first loaded.
Instance init blocks run every time a class instance is created.
Instance init blocks run after the constructor's call to super().

class SmallInit {
  static int x;

  int y;

  static {
    x = 7;
  } // static init block
  {
    y = 8;
  } // instance init block
}

class Init {
  Init(int x) {
    System.out.println("1-arg const");
  }

  Init() {
    System.out.println("no-arg const");
  }

  static {
    System.out.println("1st static init");
  }
  {
    System.out.println("1st instance init");
  }
  {
    System.out.println("2nd instance init");
  }
  static {
    System.out.println("2nd static init");
  }

  public static void main(String[] args) {
    new Init();
    new Init(7);
  }
}

1st static init
2nd static init
1st instance init
2nd instance init
no-arg const
1st instance init
2nd instance init
1-arg const