java进阶- 继承 -super ，-方法重写 -权限修饰符在继承中 -构造方法的访问特点27

 

 

 

 

package com.inherit;

public class day {
//    提高代码的复用性
    public static void main(String[] args) {
        zzz z = new zzz();
        z.setName("张三");
        z.setAge(23);
        System.out.println(z.getName()+z.getAge());
    }
}
//父
class fff {
    private String name;
    private int 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;
    }
}
//子
class zzz extends fff{

}

　　

 

 

 

 

 

 

 

 

 

 

 

 super：

 

 

 

package com.inherit;

public class day02 {
//    子父类中,出现了方法声明一模一样的方法(方法名,参数,返回值)
//    在创建子类对象,调用方法的时候,会优先使用子类的方法逻辑
//    这虽然是就近原则的现象,但其实是子类的方法,对父类的方法,进行了重写操作
    public static void main(String[] args) {
        zi z = new zi();
        z.method();
        z.show();
    }
}
class fu {
//    private String name;
    int age = 10;
    public void show(){
        System.out.println("fu");
    }
}
class zi extends fu{
    int age = 120;

    public void method() {
        int age = 1200;
        System.out.println(age);
        System.out.println(this.age);
        System.out.println(super.age);
    }
    public void show(){
        System.out.println("zi");
    }
}

　　

 

 

 

package com.inherit;

public class overwrite {
    //    方法重载(overload):在同一个类中,方法名相同,参数不同,与返回值无关
//              参数不同:类型不同,个数不同,顺序不同
//    方法重写(Override):在子父类当中,出现了方法声明一模一样的方法(方法名,参数,返回值)
//    目标1:能够独立识别出,方法是不是重写的方法
//          注解:@0 verride
//    目标2:方法重写的使用场景当子类需要父类的方法,但是觉得父类的方法逻辑不好〔修改丨增强)就可以对父类的方法进行重写
    public static void main(String[] args) {
        son s = new son();
        s.method();
    }
}
class father{
    //父类中私有方法不能重写
    public void method(){
        System.out.println("抢");
        System.out.println("结婚");
        System.out.println("压寨夫人");
    }
}
class son extends father{
    //重写父类时，子类权限必须大于父类
    @Override
    public void method() {
        super.method();
        System.out.println("礼物");
    }
}

　　

 

 

 

package com.inherit;

public class dai4 {
    public static void main(String[] args) {
        C c = new C();
        c.methodA();
        c.methodB();
        c.methodC();
    }
}
class A{
    public void methodA() {
        System.out.println("a");
    }
}
class B extends A{
    public void methodB() {
        System.out.println("b");
    }
}
class C extends B{
    public void methodC() {
        System.out.println("c");
    }
}

　　构造方法的访问特点：

 

 

案例：

package com.inherit;

public class day6 {
    public static void main(String[] args) {
        teacher t = new teacher("张伟", 23);
        t.teacher();
        stu stu = new stu("李四", 20, 100);
        stu.stu();
    }
}

class human {
    private String name;
    private int age;

    public human() {
    }

    public human(String name, int age) {
        this.name = name;
        this.age = age;
    }

    /**
     * 获取
     *
     * @return name
     */
    public String getName() {
        return name;
    }

    /**
     * 设置
     *
     * @param name
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * 获取
     *
     * @return age
     */
    public int getAge() {
        return age;
    }

    /**
     * 设置
     *
     * @param age
     */
    public void setAge(int age) {
        this.age = age;
    }

}

class teacher extends human {
    public teacher() {
    }

    public teacher(String name, int age) {
        super(name, age);
    }

    public void teacher() {
        System.out.println("姓名为" + getName() + "的" + getAge() + "岁的老师为你讲课");
    }
}

class stu extends teacher {
    private double score;

    public stu(double score) {
        this.score = score;
    }

    public stu(String name, int age, double score) {
        super(name, age);
        this.score = score;
    }

    public void stu() {
        System.out.println("姓名为" + super.getName() + "的" + super.getAge() + "岁的学生正在为自己" + score + "的成绩发愁");
    }
}

　　

 

 

案例：
package com.staff;

public class staff {
    private String name;
    private int age;
    private double salary;

    public staff() {
    }

    public staff(String name, int age, double salary) {
        this.name = name;
        this.age = age;
        this.salary = salary;
    }

    /**
     * 获取
     * @return name
     */
    public String getName() {
        return name;
    }

    /**
     * 设置
     * @param name
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * 获取
     * @return age
     */
    public int getAge() {
        return age;
    }

    /**
     * 设置
     * @param age
     */
    public void setAge(int age) {
        this.age = age;
    }

    /**
     * 获取
     * @return salary
     */
    public double getSalary() {
        return salary;
    }

    /**
     * 设置
     * @param salary
     */
    public void setSalary(double salary) {
        this.salary = salary;
    }
}

package com.staff;

public class programmer extends staff {
    public programmer() {
    }

    public programmer(String name, int age, double salary) {
        super(name, age, salary);
    }

    public void programmer() {
        System.out.println("姓名为" + getName() + "的" + getAge() + "岁的工资为" + getSalary());
    }
}

class manager extends programmer {
    private int money;

    public manager(int money) {
        this.money = money;
    }

    public manager(String name, int age, double salary, int money) {
        super(name, age, salary);
        this.money = money;
    }

    public void manager() {
        System.out.println("姓名为" + getName() + "的" + getAge() + "岁的工资为" + getSalary() + "还有" + money + "的奖金");
    }
}

package com.staff;

public class test {
    public static void main(String[] args) {
        programmer pr = new programmer("张三",23,1500.00);
        manager pr2 = new manager("李四",26,18000,5000);
        pr.programmer();
        pr2.manager();
    }
}