super,this,块，继承的应用实例

public class Person {
public Person(){
this(3);
System.out.println("3333333333");
}
public Person(int a){
this("2");
System.out.println(a);
}
public Person(String b){
System.out.println(b);
}
}

***********************************

public class Student extends Person {
{
System.out.println("2222111");
}
public Student(){
System.out.println("2222");
}
}

****************************************

public class thisdmo {
public static void main(String[] args) {
Student student =new Student();
}
}

*****************************

打印出来是：

2
3
3333333333
2222111
2222