javacore - chapter5 - 构造器、子类与父类继承关系、super与this关键字用法 demo1-3

super：

调用超类的方法调用超类的构造器
this：引用隐式参数调用该类的其它构造器

注意：
如果子类的构造器没有显示地调用超类的构造器，则将自动的调用超类默认的构造器。如果超类没有不带参数的构造器，并且在子类的构造器中又没有显式的调用超类的构造器，则Java编译器将会爆出编译错误❌。

一个对象变量，例如变量e可以只是多种实际类型的现象被称为多态，在运行时能够自动的选择调用那个方法的现象被称为多态绑定。

继承关系父类-employee

package corejava.chapter5;

import java.time.LocalDate;


public class Employee {
    private String name;
    private double salary;
    private LocalDate hireDay;

    public Employee(String name, double salary, int year, int month, int day){
        this.name = name;
        this.salary = salary;
        this.hireDay = LocalDate.of(year , month, day);
    }

    public String getName() {
        return name;
    }

    public double getSalary() {
        return salary;
    }

    public LocalDate getHireDay() {
        return hireDay;
    }

    public void raiseSalary(double byPercent){
        double raise = salary* byPercent / 100;
        salary = salary + raise;
    }
}

继承关系的子类-管理者，特殊的员工，有特殊的新手计算方式

package corejava.chapter5;


public class Manager extends Employee{

    private double bonus;

    public Manager(String name, double salary, int year, int month, int day) {
        super(name, salary, year, month, day);
        bonus = 0;
    }

    public double getSalary(){
        double baseSalary = super.getSalary();
        return baseSalary + bonus;
    }

    public void setBonus(double bonus) {
        this.bonus = bonus;
    }
}

调用计算的方法计算员工工资：父类+子类

package corejava.chapter5;


public class ManagerTest {
    public static void main(String[] args) {
        // construct a Manager object
        Manager boss = new Manager("CC", 80000, 1999, 12, 11);
        boss.setBonus(200);

        Employee[] staff = new Employee[3];
        staff[0] = boss;
        staff[1] = new Employee("王三狗", 6000, 2020, 10, 10);
        staff[2] = new Employee("王小五", 100000, 2022, 12, 12);

        for (Employee employee : staff) {
            System.out.println("name = " + employee.getName() + ",salary = " + employee.getSalary());
        }
    }
}