案例

package overrideExercise;
//编写一个Person类，包括属性/private（name、age），构造器、方法say(返回自我介绍的字符串）
public class Person {
    private String name;
    private int age;
    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }
    public String say() {
        return "name=" + name + " age=" + age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
}

package overrideExercise;
//编写一个Student类，继承Person类，增加id、score属性/private，以及构造器，定义say方法(返回自我介绍的信息)。
public class Student extends Person{
    private int id;
    private double score;
    public Student(String name, int age, int id, double score) {
        super(name, age);//这里会调用父类构造器
        this.id = id;
        this.score = score;
    }
    //say
    @Override
    public String say() { //这里体现super的一个好处，代码复用.
        return super.say() + " id=" + id + " score=" + score;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public double getScore() {
        return score;
    }
    public void setScore(double score) {
        this.score = score;
    }
}

package overrideExercise;
public class Test {
    public static void main(String[] args) {
        //在main中,分别创建Person和Student对象，调用say方法输出自我介绍
        Person jack = new Person("jack", 10);
        System.out.println(jack.say());
        Student smith = new Student("WTY", 20, 123456, 99.8);
        System.out.println(smith.say());
    }
}