class person 
{ 
  person(){System.out.println("父类-person");} 
  person(int z){} 
} 
class student extends person 
{ 
// student(int x ,int y){super(8);} 
} 
 
class Rt 
{ 
  public static void main(String[]args) 
  { 
    student student_dx=new student();//创建student类的对象 
  } 
} 
//输出结果:父类-person 

class person 
{ 
  person(){System.out.println("父类-person");} 
  person(int z){} 
} 
class student extends person 
{ 
  student(int x ,int y){super(8);} 
} 
 
class Rt 
{ 
  public static void main(String[]args) 
  { 
    student student_dx=new student(3,4);//创建student类的对象 
  } 
} 
//没有输出结果 

class person 
{ 
  person(int z){} 
} 
class student extends person 
{ 
 
} 
 
class Rt 
{ 
  public static void main(String[]args) 
  { 
    student student_dx=new student();//创建student类的对象 
  } 
} 
/*报错: 
exercise14.java:8: 找不到符号 
符号： 构造函数 person() 
位置： 类 person 
class student extends person 
^ 
1 错误 
*/