java_章节作业

第1题

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package com.hspedu.homework;/*** @author:寰愬悏瓒�* @date:2024/12/19 version:1.0*/
public class Homework01 {public static void main(String[] args) {//初始化Person对象数组，有3个Person对象；Person[] persons = new Person[3];persons[0] = new Person("tom", 87, "医生");persons[1] = new Person("jack", 28, "老师");persons[2] = new Person("smith", 56, "护士");Person temp = null;for (int i = 0; i < persons.length-1; i++) {for (int j = 0; j < persons.length - 1 - i; j++) {if(persons[j].getAge() > persons[j+1].getAge()){temp = persons[j];persons[j] = persons[j+1];persons[j+1] = temp;}}}//输出结果for (int i = 0; i < persons.length; i++) {System.out.println(persons[i].toString());}}static class Person {private String name;private int age;private String job;public Person(String name, int age, String job) {this.name = name;this.age = age;this.job = job;}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 String getJob() {return job;}public void setJob(String job) {this.job = job;}@Overridepublic String toString() {return "Person{" +"name='" + name + '\'' +", age=" + age +", job='" + job + '\'' +'}';}}
}

第2题

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第3题

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Teacher类

package com.hspedu.homework;/*** @author:寰愬悏瓒�* @date:2024/12/20 version:1.0*/
public class Teacher {private String name;private int age;private String post;private double salary;//这里需要我们增加一个工资级别private double grade;public Teacher(String name, int age, String post, double salary, double grade) {this.name = name;this.age = age;this.post = post;this.salary = salary;this.grade = grade;}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 String getPost() {return post;}public void setPost(String post) {this.post = post;}public double getSalary() {return salary;}public void setSalary(double salary) {this.salary = salary;}public double getGrade() {return grade;}public void setGrade(double grade) {this.grade = grade;}public void introduce() {System.out.println("姓名：" + name + " 年龄：" + age + " 职称：" + post + " 基本工资：" + salary + " 工资级别：" + grade);}
}

Professor类

package com.hspedu.homework;/*** @author:寰愬悏瓒�* @date:2024/12/20 version:1.0*/
public class Professor extends Teacher {public Professor(String name, int age, String post, double salary, double grade) {super(name, age, post, salary, grade);}@Overridepublic void introduce() {System.out.println("这是教授的基本信息");super.introduce();}
}

Homework3

package com.hspedu.homework;import jdk.nashorn.internal.ir.CallNode;public class Homework03 {public static void main(String[] args) {Professor professor = new Professor("林老师",30,"高级职称",30000,1.3);professor.introduce();}
}

第4题

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Worker类

package com.hspedu.homework;/*** @author:寰愬悏瓒�* @date:2024/12/20 version:1.0*/
public class Worker {private String name;private double salary;private int day;// 需要一个等级private double garde;public Worker(String name, double salary, int day, double garde) {this.name = name;this.salary = salary;this.day = day;this.garde = garde;}public String getName() {return name;}public void setName(String name) {this.name = name;}public double getSalary() {return salary;}public void setSalary(double salary) {this.salary = salary;}public int getDay() {return day;}public void setDay(int day) {this.day = day;}public double getGarde() {return garde;}public void setGarde(double garde) {this.garde = garde;}public void print() {System.out.println(name + " 工资为：" + salary*day*garde);}
}

PTworker类

package com.hspedu.homework;/*** @author:寰愬悏瓒�* @date:2024/12/20 version:1.0*/
public class PTworker extends Worker{public PTworker(String name, double salary, int day, double garde) {super(name, salary, day, garde);}@Overridepublic void print() {System.out.print("普通员工");super.print();}
}

MAworker类

package com.hspedu.homework;/*** @author:寰愬悏瓒�* @date:2024/12/20 version:1.0*/
public class MAworker extends Worker{//特有属性private double bonus;public MAworker(String name, double salary, int day, double garde) {super(name, salary, day, garde);}public double getBonus() {return bonus;}public void setBonus(double bonus) {this.bonus = bonus;}@Overridepublic void print() {System.out.println("部门经理" + getName()+" 工资为：" + (bonus+getSalary()*getDay()*getGarde()));}
}

Homework04类

package com.hspedu.homework;/*** @author:寰愬悏瓒�* @date:2024/12/20 version:1.0*/
public class Homework04 {public static void main(String[] args) {PTworker jack = new PTworker("jack", 260, 20, 1.0);MAworker tom = new MAworker("tom", 500, 25, 1.2);//设置奖金tom.setBonus(3000);jack.print();tom.print();}
}

第5题

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Yugong类

package com.hspedu.homework.homework5;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class Yungong {private String name;private double sal;//带薪月数private int salMonth = 12;public Yungong(String name, double sal) {this.name = name;this.sal = sal;}public String getName() {return name;}public void setName(String name) {this.name = name;}public double getSal() {return sal;}public void setSal(double sal) {this.sal = sal;}public int getSalMonth() {return salMonth;}public void setSalMonth(int salMonth) {this.salMonth = salMonth;}//打印工资public void print_() {System.out.println(name + " 的全年工资为：" + (salMonth * sal));}
}

Worker

package com.hspedu.homework.homework5;import java.io.StringReader;public class Worker extends Yungong{public Worker(String name, double sal) {super(name, sal);}//打印工资@Overridepublic void print_() {super.print_();}
}

Peasant

package com.hspedu.homework.homework5;public class Peasant extends Yungong{public Peasant(String name, double sal) {super(name, sal);}//打印工资@Overridepublic void print_() {super.print_();}
}

Teacher类

package com.hspedu.homework.homework5;import java.util.SplittableRandom;public class Teacher extends Yungong{//一年上的多少节课private double classDay;//课时费private double classSal;public Teacher(String name, double sal) {super(name, sal);}public double getClassDay() {return classDay;}public void setClassDay(double classDay) {this.classDay = classDay;}public double getClassSal() {return classSal;}public void setClassSal(double classSal) {this.classSal = classSal;}//打印工资@Overridepublic void print_() {System.out.println(getName() + " 全年工资为：" + (getSalMonth() * getSal() + getClassDay() * getClassSal()));}
}

Scientist

package com.hspedu.homework.homework5;import com.sun.xml.internal.ws.api.model.wsdl.WSDLOutput;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class Scientist extends Yungong{private double bonus;public Scientist(String name, double sal) {super(name, sal);}public double getBonus() {return bonus;}public void setBonus(double bonus) {this.bonus = bonus;}//打印工资@Overridepublic void print_() {System.out.println(getName() + " 全年工资为：" + (getSalMonth() * getSal() + getBonus()));}
}

Waiter

package com.hspedu.homework.homework5;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class Waiter extends Yungong{public Waiter(String name, double sal) {super(name, sal);}//打印工资@Overridepublic void print_() {super.print_();}
}

测试类Homework05

package com.hspedu.homework.homework5;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class Homework05 {public static void main(String[] args) {Worker jack = new Worker("jack", 1000);Peasant tom = new Peasant("tom", 500);Teacher sim = new Teacher("sim", 3500);sim.setClassDay(300);sim.setClassSal(1000);Scientist scient = new Scientist("scient", 6000);scient.setBonus(10000);Waiter wait = new Waiter("wait", 2000);jack.print_();tom.print_();sim.print_();scient.print_();wait.print_();}
}

第6题

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super从父类（不局限于直接父类）开始，不找本类；this从本类开始查找，再找父类

super（父类对象）可以访问父类及以上，除了 private修饰、静态、覆盖的成员
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this访问不了父类中被重写(或者说覆盖)的属性和方法
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第7题

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代码

package com.hspedu.homework;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class Homework07 {
}class Test{String name = "Rose";Test() {System.out.println("Test");//(1)Test}Test(String name) {this.name = name; //将Test类的 name 修改为 john}
}class Demo extends Test{String name = "Jack";Demo() {super();System.out.println("Demo");//(2)Demo}Demo(String s) {super(s); //s == john}public void test() {System.out.println(super.name);//(3)Rose (5)johnSystem.out.println(this.name);//(4)Jack  (6) Jack}//程序从这里开始执行public static void main(String[] args) {new Demo().test();new Demo("john").test();}
}

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第8题

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BankAccount

package com.hspedu.homework;import com.sun.corba.se.impl.ior.ObjectAdapterIdNumber;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class BankAccount {//父类private double balance; //余额public BankAccount(double initialBalance) {this.balance = initialBalance;}//存款public void deposit(double amount) {balance += amount;}//取款public void withdraw(double amount) {balance -= amount;}public double getBalance() {return balance;}public void setBalance(double balance) {this.balance = balance;}
}

CheckingAccount

package com.hspedu.homework;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class CheckingAccount extends BankAccount {public CheckingAccount(double initialBalance) {super(initialBalance);}@Overridepublic void deposit(double amount) {super.deposit(amount-1);//1块钱入银行的账户}@Overridepublic void withdraw(double amount) {super.withdraw(amount+1);//1块钱入银行的账户}
}

SavingsAccount

package com.hspedu.homework;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class SavingsAccount extends BankAccount {private  int count = 3;private double rate = 0.01; //利率public SavingsAccount(double initialBalance) {super(initialBalance);}public int getCount() {return count;}public void setCount(int count) {this.count = count;}public double getRate() {return rate;}public void setRate(double rate) {this.rate = rate;}//每个月初，统计上个月的利息，并重置 减免手续费次数的值 count = 3;public void  earnMonthlyInterest(){count = 3;super.deposit(getBalance() * rate);}//重写存款方法@Overridepublic void deposit(double amount) {//存款//判断是否还可以免手续费if(count > 0){super.deposit(amount);} else {super.deposit(amount-1);}count--; //减去一次}//重写 取款方法@Overridepublic void withdraw(double amount) { //取款//判断是否还可以免手续费if(count > 0) {super.withdraw(amount);  //1块转入银行账户} else {super.withdraw(amount+1);}count--; //减去一次}
}

Homework08

package com.hspedu.homework;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class Homework08 {public static void main(String[] args) {
//        CheckingAccount checkingAccount = new CheckingAccount(1000);
//        checkingAccount.deposit(10);//存10块，-1手续费 1009
//        checkingAccount.withdraw(10);//取10块，-1手续费 998
//
//        System.out.println(checkingAccount.getBalance());SavingsAccount savingsAccount = new SavingsAccount(1000);savingsAccount.deposit(100);//存款100 免手续费savingsAccount.deposit(100);//存款100 免手续费savingsAccount.deposit(100);//存款100 免手续费System.out.println(savingsAccount.getBalance());//余额 1300savingsAccount.deposit(100);//手续费 -1System.out.println(savingsAccount.getBalance());//余额 1300+100-1=1399//      //月初，定时器自动调用一下， earnMonthlyInterestsavingsAccount.earnMonthlyInterest();//统计利息System.out.println(savingsAccount.getBalance());//1399 + 13.99=savingsAccount.deposit(100);//存款100 免手续费savingsAccount.deposit(100);//存款100 免手续费savingsAccount.deposit(100);//存款100 免手续费}
}

第9题

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Point

package com.hspedu.homework;public class Point {private double x;private double y;public Point(double x, double y) {this.x = x;this.y = y;}
}

LabeledPoint

package com.hspedu.homework;import com.hspedu.homework.Point;public class LabeledPoint extends Point {private String label;public LabeledPoint( String label,double x, double y) {super(x, y);this.label = label;}
}

Homework09

package com.hspedu.homework;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class Homework09 {public static void main(String[] args) {new LabeledPoint("Black",1929,230.04);}
}

第10题

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Doctor

package com.hspedu.homework;import javax.print.Doc;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class Doctor {private String name;private int age;private String job;private char gender;private double sal;public Doctor(String name, int age, String job, char gender, double sal) {this.name = name;this.age = age;this.job = job;this.gender = gender;this.sal = sal;}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 String getJob() {return job;}public void setJob(String job) {this.job = job;}public char getGender() {return gender;}public void setGender(char gender) {this.gender = gender;}public double getSal() {return sal;}public void setSal(double sal) {this.sal = sal;}@Overridepublic boolean equals(Object obj) {//判断两个比较对象是否相同if(this == obj) {return true;}//判断obj 是否是 Doctor类型或其子类//过关斩将 校验方式if(! (obj instanceof Doctor)){ //不是的话return false;}//这里因为 编译类型是 object，无法访问Doctor属性，// 所以需要向下转型Doctor doctor = (Doctor)obj;return this.name.equals(doctor.name) && this.age == doctor.age && this.gender == doctor.gender && this.job.equals(doctor.job) && this.sal == doctor.sal;}
}

Homework10

package com.hspedu.homework;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class Homework10 {public static void main(String[] args) {Doctor doctor1 = new Doctor("jack", 20, "医生", '男', 20000);Doctor doctor2 = new Doctor("jack", 20, "医生", '男', 20000);System.out.println(doctor1.equals(doctor2));//true}
}

第11题

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向上转型：父类的引用指向子类的对象

Person  p = new Student();
p.run(); // 能调用父类的run(),实际运行的是子类的run();
p.eat();//能调用父类的eat()，因为子类中没有eat(),所以执行的是父类的eat();

编译看左边（父类），执行看右边

意思就是向上转型只能找到父类方法，运行的时候就得看运行类型怎么说了,如果Student类有相同的方法，那就执行Student类的；如果没有，那就去父类找，有就执行；

向下转型：把指向子类对象的父类引用，转成指向子类对象的子类引用
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第12题

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第13题

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Person

package com.hspedu.homework.homework13;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class Person {private String name;private char sex;private int age;public Person(String name, char sex, int age) {this.name = name;this.sex = sex;this.age = age;}public String getName() {return name;}public void setName(String name) {this.name = name;}public char getSex() {return sex;}public void setSex(char sex) {this.sex = sex;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}//玩的方法public String play() {return name + "爱玩";}//打印方法public String basicInfo() {return "性别：" + name + "\n年龄：" + age + "\n性别：" + sex;}@Overridepublic String toString() {return "name='" + name + '\'' +", sex=" + sex +", age=" + age +",";}
}

Student

package com.hspedu.homework.homework13;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class Student extends Person{private String stu_id;public Student(String name, char sex, int age, String stu_id) {super(name, sex, age);this.stu_id = stu_id;}public String getStu_id() {return stu_id;}public void setStu_id(String stu_id) {this.stu_id = stu_id;}public void study() {System.out.println("我承诺，我会好好学习");}@Overridepublic String play() {return super.play() + "足球";}//编写一个输出信息的方法,这样体现封装public void printInfo() {System.out.println("学生的信息：");System.out.println(super.basicInfo());System.out.println("学号：" + stu_id);study();System.out.println(play());}@Overridepublic String toString() {return "Student{" +super.toString()+"stu_id='" + stu_id + '\'' +'}';}
}

Teacher

package com.hspedu.homework.homework13;/*** @author:寰愬悏瓒�* @date:2024/12/21 version:1.0*/
public class Teacher extends Person{private int work_age;public Teacher(String name, char sex, int age, int work_age) {super(name, sex, age);this.work_age = work_age;}public int getWork_age() {return work_age;}public void setWork_age(int work_age) {this.work_age = work_age;}public void teach(){System.out.println("我承诺，我会认真教学");}@Overridepublic String play() {return super.play() +"象棋";}public void printInfo() {System.out.println("老师的信息：");System.out.println(super.basicInfo());System.out.println("工龄：" + work_age);teach();System.out.println(play());}@Overridepublic String toString() {return "Teacher{" + super.toString() +"work_age=" + work_age +'}';}
}

Homework13

package com.hspedu.homework.homework13;public class Homework13 {public static void main(String[] args) {
//        Teacher teacher = new Teacher("张飞", '男', 30, 5);
//        teacher.printInfo();
//        System.out.println("---------------------------");
//
//        Student student = new Student("小明", '男', 15, "00023102");
//        student.printInfo();Person[] person= new Person[4];person[0] = new Student("tom", '男', 23,"00001");person[1] = new Student("ming", '男', 24,"00002");person[2] = new Teacher("smith", '女', 30,10);person[3] = new Teacher("wujing", '女', 46,20);Homework13 homework13 = new Homework13();homework13.bubbleSort(person);System.out.println("-------------排序后的Person数组------------");for (int i = 0; i < person.length; i++) {System.out.println(person[i]); //这是，实际上是调用person[i].toString()}//遍历数组，调用test方法System.out.println("==================");for (int i = 0; i <person.length; i++) { //遍历多态数组homework13.test(person[i]); // test方法去判断是学生还是老师}}//排序方法-冒泡排序private void bubbleSort(Person[] person) {Person temp  = null;//按照年龄从高到低排序for (int i = 0; i < person.length-1; i++) {for (int j = 0; j < person.length-i-1; j++) {if(person[j].getAge() < person[j+1].getAge()){temp = person[j];person[j] = person[j+1];person[j+1] = temp;}}}}//定义方法，形参为Person类型，功能：调用学生的study或教师的teach方法//这里会使用到向下转型和类型判断public void test(Person p){if(p instanceof Student){ // p 的运行类型如果是Student((Student) p).study();} else if(p instanceof Teacher) { // p 的运行类型如果是 Teacher((Teacher) p).teach();} else {System.out.println("do nothing...");}}}