1、Person类
package com.yfs.javase;
//可以有多个子类
public class Person {
private String name;// 私有属性不能继承
private int age;
private char sex;
private void privateMehtod() {// 私有方法 类中可以访问
System.out.println("call privateMehtod()...");
}
public Person() {
// privateMehtod();
System.out.println("创建Perosn对象...");
}
public Person(String name) {
this.name = name;
}
public Person(String name, int age, char sex) {
this.name = name;
this.age = age;
this.sex = sex;
}
public void introduce() {
System.out.println("I am Person....");
}
public String toString() {
return "姓名：" + name + " 年龄 ：" + age + " 性别：" + sex;
}
public void speak() {
System.out.println(name + " 工作了吗？");
// privateMehtod();
}
public void sleep() {
System.out.println(name + " 睡觉了吗？");
}
public void eat() {
System.out.println(name + " 吃了吗？");
}
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;
}
public char getSex() {
return sex;
}
public void setSex(char sex) {
this.sex = sex;
}
}
2.Student类
package com.yfs.javase;
//实现代码重用 单继承
public class Student extends Person {// 继承Person
private int score;
@Override
public void introduce() {
System.out.println("I am student...");
}
// 覆盖 重写父类的方法
@Override
public String toString() {
return super.toString() + " 成绩：" + score;
}
public int getScore() {
return score;
}
public void setScore(int score) {
this.score = score;
}
public Student() {// 系统自动调用父类构造方法
// super();//调用父类无参数构造方法super() 必须第一句
// super("Jack");
System.out.println("创建Student对象...");
}
// 扩展方法
public void study() {
// getName()继承方法
// privateMethod();私有方法不能继承
// super.toString();//调用父类方法
// this super
System.out.println(getName() + " 在学习...");// 私有属性能否继承
}
}
// 子类下还可以继承
class YfsStudent extends Student {
}
3.Teacher类
package com.yfs.javase;
public class Teacher extends Person {
@Override
public void introduce(/*int a*/) {
System.out.println("I am teacher...");
}
}
4.Person测试
package com.yfs.javase;
public class PersonTest {
public static void main(String[] args) {
Person p1 = new Person();
p1.setName("张三");
p1.setAge(20);
p1.setSex('男');
System.out.println(p1);//默认toString方法
Student s1 = new Student();
s1.setName("李四");
s1.setAge(22);
s1.setSex('女');
System.out.println(s1);
Teacher t1 = new Teacher();
t1.setName("王五");
t1.setAge(30);
t1.setSex('男');
System.out.println(t1);
YfsStudent ys = new YfsStudent();
ys.setName("Tom");
System.out.println(ys);
//ys.
s1.study();
//p1.study();//父类不能调用子类方法
ys.study();
}
}
5.Student测试
package com.yfs.javase;
public class StudentTest {
public static void main(String[] args) {
//构造方法不能继承
//Student s1 = new Student("zhangsan",20,'男');
//Student s2 = new Student("lisi");
Student s3 = new Student();//系统提供构造方法
s3.setName("李四");
s3.speak();
System.out.println(s3);
s3.eat();
Teacher t1 = new Teacher();
t1.setName("张飞");
t1.eat();
System.out.println(t1);
//Person p1 = new Person("张三",23,'男');
}
}
6.Teacher类测试
package com.yfs.javase;
public class TeacherTest {
public static void main(String[] args) {
Person p1 = new Person();
p1.setName("张三");
Student s1 = new Student();
s1.setName("李四");
Teacher t1 = new Teacher();
t1.setName("王五");
p1.introduce();
s1.introduce();
t1.introduce();
}
}