Java Object initializer

[Ramesh Pramuditha Rathnayake]

I've heard that, java object initializer do 3 things in the following order.

1. Initialize non static attributes.
2. Run non static blocks.
3. Run the constructor.

But compiler gives error in following code..

public class Example{
	{
		System.out.println(x);
	}
	int x = 100;
	public static void main(String args[]){
		//
	}
}

But there is no error in the following code.

public class Example{
	int x = 100;
	{
		System.out.println(x);
	}
	public static void main(String args[]){
		//
	}
}

What is the reason..?

[Campbell Ritchie]

Your informant was mistaken about initialisers running the constructor. That is done by the JVM when the new operator is used. You can find out how it is done in the Java Language Specification (I hope I quoted the right section).
Unlike in the rest of the class, the order of members is significant to initialisers. The field must be declared and definitely assigned before it is available to the initialiser. So your first example, where the initialiser preceded the field, is invalid.