java初始化过程中成员变量

package day01;
class Base{
int j;  //1.j=0
Base(){
add(1);   //2.调用子类add()方法
System.out.println(j); //4,父类j=0，打印0
}
public void add(int i) {
j=j+1;
}
}
class MyBase extends Base{
int j=5;              //5,j=5
MyBase(){
System.out.println(j);   //打印5
}
public void add(int i) {
j=j+i+1;
System.out.println(j);     //3, 此时子类j还没显示初始化，默认值0，j=2，打印2
}
}
public class Tester {
public static void main(String[] args) {
new MyBase();
}
}

package day01;
class Base{
public  int j;  //1.j=0
Base(){
add(1);   //2.调用子类add()方法
System.out.println(j); //4,这里为什么打印2，不该是0吗？why?
}
public void add(int i) {
j=j+1;
}
}
class MyBase extends Base{

MyBase(){
System.out.println(j);
}
public void add(int i) {
j=j+i+1;
System.out.println(j);     //3, 此时子类j还没显示初始化，默认值0，j=2，打印2
}
}
public class Tester {
public static void main(String[] args) {
new MyBase();
}
}
/* 2
* 2
* 2
*/