每日代码系列（17）

interface Achievement {
  public abstract float average();
}
class Person {
  String name;
  int age;
  public Person(String newName,int newAge) {
    name=newName;
    age=newAge;
  }
  public void introduce() {
    System.out.println("你好,我是"+name+",今年"+age+"岁");
  }
}
class Student extends Person implements Achievement {
  int chinese,math,english;
  public Student(String newName,int newAge) {
    super(newName,newAge);
  }
  public void setScore(int c,int m,int e) {
    chinese=c;
    math=m;
    english=e;
  }
  public float average() {
    return (chinese+math+english)/3;
  }
}
class C3_2 {
  public static void main(String[] args) {
    Student s1=new Student("张三",16);
    s1.introduce();
    s1.setScore(80,90,80);
    System.out.println("平均分: "+s1.average());
  }
}

补上周六欠的。