Hi,

If you compile then decompile your code, you'll find that your variables are
put into the constructor and set in there.
You should also notice that if you have multiple constructors then the same
initialisation is done in each, hence potentially bloating the class file
uneccessarily.

one way to reduce this is to always initialize your vars inside one
constructor, and in each additional constructor simply call the default
constructor first..

example:

Source code:

public class Sample {

   int a = 1;
   int b = 2;
   int c = 3;

   public Sample() {
   }

   public Sample(int d) {
   }
}

Decompiled:

public class Sample
{

   int a;
   int b;
   int c;

   public Sample()
   {
       a = 1;
       b = 2;
       c = 3;
   }

   public Sample(int d)
   {
       a = 1;
       b = 2;
       c = 3;
   }
}

Using default constructor....
Source:
public class Sample {

   int a;
   int b;
   int c;

   public Sample() {
       a=1;
       b=2;
       c=3;
   }

   public Sample(int d) {
       this();
   }
}

Decompiled:

public class Sample
{

   int a;
   int b;
   int c;

   public Sample()
   {
       a = 1;
       b = 2;
       c = 3;
   }

   public Sample(int d)
   {
       this();
   }
}

As you can see, if you have many constructors and many variables, you could
indeed have a rather bloated compiled class.

Hope this helps,

Steve

Actually it's equivalent to this code:

class A {
   int a = 0;
   {
       a = 5;
   }
   A() { }
}

because field initializations are put into every constructor, and
hence can be thought of as being in an instance initializer block.

Yes, the initialization to 0 happens first: This is done by the "new"
instruction, which occurs before the constructor is called.