un-named block of code

[Jitendra Jha]

while reading i came across this block of code

public class unspec
{
{
System.out.println("Hello");
}
unspec()
{
System.out.println("Hello World");
}
public static void main(String args[])
{
unspec us=new unspec();
}
}


this block of code compiles and the unnamed block is executed first,even before constructor.
What is this block and what is its purpose.

please guide me

[Henry Wong]

That "block of code" ...

{
   System.out.println("Hello");
}

is called an instance initializer. It is executed along with the initialization of your instance variables. In terms of when, it is executed after the super constructor, but before the constructor.

Henry

[Jitendra Jha]

With due respect Henry,it still is not very clear.would you or anyone else please explain it.sorry and thanks for the trouble

[Henry Wong]

Originally posted by Jitendra Jha:
With due respect Henry,it still is not very clear.would you or anyone else please explain it.sorry and thanks for the trouble

With due respect, can you tell us what you are not clear with? We can't read your mind, and just repeating ourselves with different words or examples, is not a very efficient.

Henry

[Ilja Preuss]

Take a look at http://java.sun.com/developer/JDCTechTips/2004/tt0406.html#2

Googling for "instance initializer", it was the first hit.

[Jesper de Jong]

Try searching for "java instance initializer" with Google, and you'll find a number of pages that explain what it is. Maybe these are useful:

The Essence of OOP using Java, Instance Initializers
The Java Tutorial - Initializing Fields (see the bottom of the page)
JavaWorld: Object initialization in Java