1、封装一个类Student
(1) 属性:学号、名字、年龄、性别
(2) 方法:吃饭、跑步、睡觉
(3) 属性私有化
(4) 添加访问属性的 get 和 set 方法。
(5) 在类中添加构造方法
无参构造方法
有参构造方法-在构造方法中初始化学生的各个属性值
(6) 创建类 Test 中添加主函数
(7) 在主函数中实例化 2 个 Student 类的对象,分别给属性赋值
其中一个对象直接使用带参构造方法创建
1个对象使用无参构造方法创建,创建后使用set方法给属性赋值
(8) 输出并调用所有的方法
(9) 输出每个对象的详细信息
方法区:
public class Student {
//属性
private int xuehao;
private String name;
private int age;
private String sex;
//方法
//无参
public Student() {
}
//有参
public Student(int xuehao,String name,int age,String sex) {
this.xuehao=xuehao;
this.name=name;
this.age=age;
this.sex=sex;
}
public static void wan() {
System.out.println("玩");
}
public void eat () {
System.out.println(name+"爱吃饭");
}
public void sleep() {
System.out.println(name+"爱睡觉");
}
public void run() {
System.out.println(name+"爱跑步");
}
public void setXuehao(int xuehao) {
this.xuehao=xuehao;
}
public int getXuehao() {
return xuehao;
}
public void setName(String name) {
this.name=name;
}
public String getName() {
return name;
}
public void setAge( int age) {
this.age=age;
}
public int getAge() {
return age;
}
public void setSex(String sex) {
this.sex=sex;
}
public String getSex() {
return sex;
}
public String getInfo() {
return "姓名:"+name+"学号:"+xuehao+"性别:"+sex+"年龄:"+age;
}
}
测试区:
public class StudentTest {
public static void main(String[] args) {
//夏洛
Student xialuo=new Student(1234567,"夏洛",18,"男");
System.out.println(xialuo.getInfo());
xialuo.eat();
xialuo.sleep();
xialuo.run();
//马冬梅
Student m=new Student();
m.setXuehao(7654321);
m.setName("马冬梅");
m.setAge(17);
m.setSex("女");
System.out.println(m.getInfo());
m.eat();
m.sleep();
m.run();
Student.wan();
}
2、封装一个类 Dog
属性有 name type color age sex
方法有 eat run sleep
属性私有化添加访问属性的get和set 方法 添加有参数和无参数的构造函数。
创建类 Test 中添加主函数,在主函数中实例化3个Dog类的对象分别给属性赋值,输出并调用所有的
方法区:
public class Dog {
private String name;
private String type;
private String color;
private int age;
private String sex;
//无参
public Dog() {
}
//有参
public Dog(String name, String type, String color, int age, String sex) {
this.name = name;
this.type = type;
this.color = color;
this.age = age;
this.sex = sex;
}
public void eat() {
System.out.println(name+"爱吃");
}
public void run() {
System.out.println(name+"爱跑步");
}
public void sleep() {
System.out.println(name+"爱睡觉");
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getColor() {
return color;
}
public void setColor(String color) {
this.color = color;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getInfo() {
return "昵称:"+name+"类型:"+type+"性别:"+sex+"年龄:"+age+"颜色"+color;
}
}
测试区:
public class DogTest {
public static void main(String[] args) {
Dog g1=new Dog("夏洛","拉布拉多","黄色",10,"男");
System.out.println(g1.getInfo());
g1.eat();
g1.run();
g1.sleep();
Dog g2=new Dog("马冬梅","萨摩耶","白色",9,"女");
System.out.println(g2.getInfo());
g2.eat();
g2.run();
g2.sleep();
Dog g3=new Dog("袁华","哈士奇","黑白色",8,"男");
System.out.println(g3.getInfo());
g3.eat();
g3.run();
g3.sleep();
}
}
3、封装一个类 Book
属性有 图书编号 图书名称 作者 价格
获取图书信息的方法
属性私有化添加访问属性的get和set 方法 添加有参数和无参数的构造函数。
创建类 Test 中添加主函数,
在主函数中创建一个数组,控制台输入5本图书信息存到数组中
将所有的图书信息打印到控制台
并获取所有图书的总价格
方法区:
public class Book {
private int num;
private String name;
private String author;
private double price;
public Book(int num, String name, String author, double price) {
this.num = num;
this.name = name;
this.author = author;
this.price = price;
}
public Book() {
}
public int getNum() {
return num;
}
public void setNum(int num) {
this.num = num;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAuthor() {
return author;
}
public void setAuthor(String author) {
this.author = author;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
// public static void bianli(Book[]arr) {
// for (int i = 0; i < arr.length; i++) {
// System.out.println(arr[i]);
// }
// }
public String getInfo() {
return "书名"+name+"作者"+author+"编号"+num+"价格"+price;
}
public double zongjiage(Book[]arr) {
double sum=0;
for (int i = 0; i < arr.length; i++) {
sum=sum+arr[i].getPrice();
}
return sum;
}
}
测试区:
public static void main(String[] args) {
Book[] arr=new Book[5];
Scanner sc=new Scanner(System.in);
for (int i = 0; i < arr.length; i++) {
System.out.println("请输入第"+(i+1)+"本书的信息");
System.out.println("书名");
String name=sc.next();
System.out.println("编号");
int num=sc.nextInt();
System.out.println("作者");
String author=sc.next();
System.out.println("价格");
double price=sc.nextDouble();
Book book=new Book(num, name, author, price);
arr[i]=book;
}
// for(Book book : arr) {
// System.out.println(book.getInfo());
// }
for (int i = 0; i < arr.length; i++) {
System.out.println(arr[i].getInfo());
}
//求价格
// double sum=0;
// for (int i = 0; i < arr.length; i++) {
// sum=sum+arr[i].getPrice();
// }
double sum=arr[1].zongjiage(arr);
System.out.println(sum);
}