How initializer blocks help to share a block of code between multiple constructors?

[Varuna Seneviratna]

http://java.sun.com/docs/books/tutorial/java/javaOO/initial.html

In this page Under Initializing Instance Members there is:

The Java compiler copies initializer blocks into every constructor. Therefore, this approach can be used to share a block of code between multiple constructors.

What is meant by the above?
[ December 15, 2008: Message edited by: Varuna Seneviratna ]

[BV Boose]

It means that the code between the curly braces will be called by every constructor of the class.

public class InitializeBlock {
 
{
System.out.println("I am an intializer block, somebody called me");
}
public InitializeBlock(){
System.out.println("I'm constructor number 1");
}

public InitializeBlock(int constructorNumber){
System.out.println("I'm constructor number " + constructorNumber);
}

public InitializeBlock(int constructorNumber, boolean status){
System.out.println("I'm constructor number " + constructorNumber);
}


/**
 * @param args
 */
public static void main(String[] args) {
InitializeBlock one = new InitializeBlock();
InitializeBlock two = new InitializeBlock(2);
InitializeBlock three = new InitializeBlock(3, false);
 
}
 
}

produces:
I am an intializer block, somebody called me
I'm constructor number 1
I am an intializer block, somebody called me
I'm constructor number 2
I am an intializer block, somebody called me
I'm constructor number 3
3 different constructors all called

[Amit Ghorpade]

Varuna, please consider making your subject line more descriptive. I can hardly make out anything of it. Read this to know why this is important. You can edit your post by clicking the .

[Amit Ghorpade]

.. and while we are on the topic, you might also want to take a look at the order in which initialization blocks and constructors are invoked.