At the time of class loading following sequence of steps is performed by JRE


At the time of class loading following sequence of steps is performed by JRE

(1). Static Data Members (if defined) are created in the Class Area.
(2). Static Initializer Block (if defined) is executed.
(3). Reference of the class which resulted in class loading is resolved i.e. operation represented by           the reference is performed.

  2. class A
  3. {
  4. static 
  5. {
  6. System.out.println(“A is loaded.”);
  7. }
  9. public A()
  10. {
  11. System.out.println(“A is instantiated.”);
  12. }
  13. }

  15. class B
  16. {
  17. static int b;
  19. static
  20. {
  21. b=5;
  22. System.out.println(“B is loaded.”);
  23. }
  24. }

  26. class C
  27. {
  28. static
  29. {
  30. System.out.println(“C is loaded.”);
  31. }
  33. public static void display( )
  34. {
  35. System.out.println(“Display( ) of C is invoked.”);
  36. }
  37. }
  39. class D
  40. {
  41. static
  42. {
  43. System.out.println(“D is loaded.”);
  44. }
  46. public static void main(String args[])
  47. {
  48. System.out.println(“Instantiating A………”);
  49. A x = new A();
  50. System.out.println(“Referencing static data member b of B……”);
  51. System.out.println(“b of B is : “ + B.b);
  52. System.out.println(“Invoking static method of C……”);
  53. C.display();
  54. System.out.println(“Instantiating A again.”);
  55. A y = new A();
  56. }
  57. }
  58.  







class E
{
               static int a = 5;
              
               public static void main(String args[])
{
System.out.println(“a = “ + a);
}


After compilation
}


class E
{
               static int a;
              
               static
{
a = 5;
}
----
----
}
-------------------------------------------------------------------------------------------------------


class E
{
               int a = 5, b=6;
              
               public static void main(String args[])
{
E x = new E();
System.out.println(“a = “ + x.a);
System.out.println(“b = “ + x.b);

}

After compilation
}



class E
{

               int a, b;


E( )
               {
a = 5;
b = 6;
}
----
----
}
-------------------------------------------------------------------------------------------------------
class E
{
               int a=5, b=6;
              
               public E ()
               {
                              System.out.println(“Default.”);
}

               public E(int x)
               {
                              a=x;
                              System.out.println(“One parameterized.”);
}

               public E(int x, int y)
               {
                              b=y;
                              System.out.println(“Two parameterized.”);
}

public void display()
{
System.out.println(“a = “ + a);
System.out.println(“b = “ + b);
}

               public static void main(String args[])
{
E x = new E();
E y = new E(10);
E z = new E(40, 50);
x.display();
y.display();
z.display();
}

}



After compilation,

the compiler will do the following for the same program



  1. class E
    {
                   int a, b;
                  
                   public E()
                   {
                                  a=5, b=6;
                                  System.out.println(“Default.”);
    }

                   public E(int x)
                   {
                                  a=5, b=6;
                                  a=x;
                                  System.out.println(“One parameterized.”);
    }

                   public E(int x, int y)
                   {
                                  a=5, b=6;
                                  b=y;
                                  System.out.println(“Two parameterized.”);
    }

    public void display()
    {
    System.out.println(“a = “ + a);
    System.out.println(“b = “ + b);
    }

                   public static void main(String args[])
    {
    E x = new E();
    E y = new E(10);
    E z = new E(40, 50);
    x.display();
    y.display();
    z.display();
    }
    }












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