class Person{
private String name;
private String location;

Person(String name){
this.name = name;
location = "Beijing";

}
Person(String name,String location){
this.name = name;
this.location = location;
}
public String info(){
return "name: "+name+" location: "+location;
}

}class Student{
private String school;
Student(String name,String school){
this(name,"Beijing",school);
}
Student(String n,String l,String school){
super(n,l);
this.school = school;
}
public String info(){
return super.info()+"school:"+school;
}
}
class Teacher extends Person{
private String captical;
Teacher(String name,String captical){
this(name,"Beijing",captical);

}
Teacher(String n,String l,String captical){
super(n,l);
this.captical = captical;
}
public String info(){
return super.info()+"captical:"+captical;
}
}

public class TestTeacher{
public static void main(String args[]){
Person p1 = new Person("A");
Person p2 = new Person("B","Shanghai");
Student s1 = new Student("s1","c1");
Student s2 = new Student("s2","Beijing","c2");
System.out.println(p1.info());
System.out.println(p2.info());
System.out.println(s1.info());
System.out.println(s2.info());
Teacher t1 = new Teacher("D","Professor");
System.out.println(t1.info());
//Teacher t2 = new Teacher("E","Shanghai","Professor");
// System.out.println(t2.info());
}
}

这是什么原因?