What are “static initializers” or “static blocks with no function names”?

I have updated in http://www.freejavaclass.com/

When a class is loaded, all blocks that are declared static and don’t have function name (i.e. static initializers) are executed even before the constructors are executed. As the name suggests they are typically used to initialize static fields.

public class StaticInitilaizer {

public static final int A = 5;

public static final int B;

//Static initializer block, which is executed only once when the class is loaded.

static {

if(A == 5)

B = 10;

else

B = 5;

}

public StaticInitilaizer(){} // constructor is called only after static initializer block

}

The following code gives an Output of A=5, B=10.

public class Test {

System.out.println("A =" + StaticInitilaizer.A + ", B =" + StaticInitilaizer.B);

}