if instance variable get initialize after assigning some values or
after constructor then when does static variable get initialize

public class A{

private int a;
private int b=0;
private Integer c;
private Integer d=new Integer(2);

public static int counter;
private A(){
}

}

by looking at above code one can say that variable b,d get initialize
by assignment operator
variable a,c by constructor to default values

i am not aware of how does variables get initialize

i think
1] static variables without assignment
2] static variables with assignment
3] instance variables with assignment
4] instance variables without assignment to default values

is it right flow of variables initializtion?