instance initializers

[Arjun Reddy]

Hi all,

Are instance initializers the labeled loops we write? Or are they something else?

Thanks.

[vidhya suvarna]

They are instance variables that belong to a class and get initialized before the constructed is called.

[Arjun Reddy]

After the constructor is called right?

[vidhya suvarna]

No, before the constructor is called.

Suppose the subclass constructor is called which invokes the superclass constructor then, 1st superclass variables are intialized and the constructor is run. Then controls come to subclass constructor where again 1st subclass variables are intialized and then the constructor run.

[Bert Bates]

how about some sample code?

[Rekha Srinath]

Am I correct if I say that in the following code, "initvar" is an instance initializer?

The output of this code is:

In Super's constructor. initvar value = 100
Done calling super() in Sub class

public class InstanceInitializer
{
public static void main (String [] args) {
Sub subobj = new Sub ();
}
}
 
class Super
{
int initvar = 100;
Super () {
System.out.println ("In Super's constructor. initvar value = " + initvar);
}
}
 
class Sub extends Super
{
Sub () {
super ();
System.out.println ("Done calling super() in Sub class");
}
}

[ September 28, 2008: Message edited by: Rekha Srinath ]

[vidhya suvarna]

Yes Rekha, thats correct.

[Arjun Reddy]

Thanks Guys.