how do variables get initialized when a blank constructor is provided

[VamC Krishna]

The class or instance variables are initialized by the constructor.
If I write a constructor, the default constructor is not inserted by the compiler,
but even if I don't initialize the variables in the constructor , the variables still get default values ...how ?

Does the <init> method initialize them by itself ??

[Campbell Ritchie]

I always thought it was because the JVM deletes all the memory which the fields will occupy, when it instantiates the object.

But I might be mistaken.

[VamC Krishna]

hmmm....
anyone know the answer ?

[Joanne Neal]

VamC Krishna wrote:The class or instance variables are initialized by the constructor.

No. Class or instance variables are initialized when they are created. You can use the constructor to change the default value.

See the Java Language Specification, Section 4.12.5.

[Campbell Ritchie]

I thought your question meant, "How are the default values initialised?"

If you want to insert different initial values, there are several ways to do it; I would prefer to see them inside the constructor. Example:

public class Foo
{
   private String name;
   private int age;

   public Foo()
   {
      name = "Campbell";
      age = 97;
   }
 . . .
}

[VamC Krishna]

Campbell Ritchie wrote:I thought your question meant, "How are the default values initialised?"

If you want to insert different initial values, there are several ways to do it; I would prefer to see them inside the constructor. Example:

public class Foo
{
   private String name;
   private int age;

   public Foo()
   {
      name = "Campbell";
      age = 97;
   }
 . . .
}

sorry !!
not really ..
consider the following Program

class Test2{
    int i;
    //blank constructor , no variable is initialized !!
    Test2(){
    }
    public static void main(String args[]){
        Test2 t = new Test2();
        System.out.println(t.i);
    }

}

Now if I run the above program I get the output as

0

........
the integer i is initialized to 0.
As I wrote a constructor, the default no-arg constructor is not created by the compiler. Then who initialized the variable.

[VamC Krishna]

Joanne Neal wrote:

VamC Krishna wrote:The class or instance variables are initialized by the constructor.

No. Class or instance variables are initialized when they are created. You can use the constructor to change the default value.

See the Java Language Specification, Section 4.12.5.

Oh ! thank you.
If possible, can you please give the page no. or chapter no. if it is readily availbable with you. Mean while I will keep searching it .
Thanks a lot

[Joanne Neal]

VamC Krishna wrote:

Joanne Neal wrote:

VamC Krishna wrote:The class or instance variables are initialized by the constructor.

No. Class or instance variables are initialized when they are created. You can use the constructor to change the default value.

See the Java Language Specification, Section 4.12.5.

Oh ! thank you.
If possible, can you please give the page no. or chapter no. if it is readily availbable with you. Mean while I will keep searching it .
Thanks a lot

Click on the link. There are then links in both the HTML and PDF versions to each of the sections.

[VamC Krishna]

Sorry,
I overlooked the section 4.12.5 part in your message, I was asking that.
I am reading that now ..
thanks