Java的初步使用

package Bill;
import java.util.Scanner;//花费时间四十，包含查询如何使用继承
public class BillWaterBill {

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
double volume =input.nextDouble();
//      Bill bill = new Bill();
//      bill.getVolume(volume);
WaterBill waterbill = new WaterBill(volume);
waterbill.getBill();

}

}

class Bill{
double volume;//使用量
public Bill(){}//这里使用public 还不确定
public Bill(double volume){
this.volume = volume;
}
double getVolume(double volume) {
this.volume = volume;
return volume;
}
double setVolume(double volume) {
return volume;
}
public double getBill() {//计算bill
return this.volume;
}

}

class WaterBill extends Bill{//能够继承public 以及protected
private double[] rate = {2.28,2.5,3.9};
WaterBill(){//系统会自动调用子类无参构造函数
}
WaterBill(double volume){//uml图中，+,-,#分别表示 public ,private,protected
this.volume = volume;
}
//  UML图包括三个部分
//  1：类名
//2：类的属性，属性是指类的成员变量，UML属性的表示方式为：可见性 名称:类型 [ = 缺省值 ]
//可见性就是私有公有保护
//  名称就是属性名，用一个字符串表示
//  类型就是数据类型，也可以是用户自定义的名称
//  缺省值，是一个可选项，就是属性的初始值
//  object 对象
//  3：类的操作：操作是类的任意一个势力对象都可以使用的行为，是类的成员方法，UML规定操作的表示方法为：可见性 名称(参数列表) [ : 返回类型]

double[] getRate() {
return this.rate;
}
void setRate(double[] rate) {
this.rate = rate;
}
public double getBill() {
double bill = 0;
if(this.volume>260) {
bill = (this.volume - 260) * this.rate[2] + 80 * rate[1] + 180 * rate[0];
}
else if(this.volume > 180) {
bill = (this.volume - 180) * rate[1] + 180 * rate[0];
}
else bill = (this.volume) * rate[0];

System.out.println("水费为"+bill);
return bill;
}

}

package Circle;
import java.util.Scanner;
class Circle{
private double radius;
Circle(){
}
Circle(double radius){
this.radius = radius ;
}
double getRadius() {
return radius ;
}
void setRadius(double speed) {
this.radius = speed;
}
double getArea() {
return radius*radius*3.14;//结果与答案相差几位小数 应该是估读的问题 但修改为3.14一样有相差
}

}

//声明静态变量-- 让一个类的所有实例共享数据
//定义方法：在定义前加static
//使用private，定义方法还有变量，达到数据封装的效果
//UML类图中，使用“-”号表示，private
//英语好好学，计算机专业很多的内容需要用到英语文献

//对象数组初始化方法
//Circle[] circleArray = new Circle[10];
//for(int i = 0;i<10;i++)
//  circleArray[i] = new Circle();

public class CircleArea {

public static void main(String[] args) {
// TODO Auto-generated method stub
//      System.out.println("hello world");
//      System.out.println(c.length);
//      sum(createCircleArray());

//      String a;//定义字符串
//      a = "new string";
//      System.out.println(a);
//      resolved 决定
String newString = "welcome to java";
//      String newString = new String("welcome to Java");
System.out.println(newString);
//      字符串在Java中是不可变的，所以定义之后是不能改变的，就是
newString = "hello world!";
System.out.println(newString);
System.out.println(newString.length());

//
printCircleArray(createCircleArray());
}

//  Create class of circle

//返回一个数组大小为三
public static Circle[]  createCircleArray() {   //创建圆类型数组
Circle [] circle = new Circle[3];
Scanner input = new Scanner(System.in);
for(int x1 = 0 ;x1<circle.length;x1++) {
double x2 = input.nextDouble();
//          System.out.println(circle[x1]);

circle[x1] = new Circle();  //数组初始化了，指针不为零，但其中的对象还没有初始化
circle[x1].setRadius(x2);

}
return circle;
}

public static double sum(Circle[] circles) {
double sum1 = 0;
for(int x = 0 ;x<circles.length;x++)

sum1+=circles[x].getArea();
return sum1;
}

public static void printCircleArray(Circle[] circles) {
System.out.println("半径              面积");
for(int x = 0;x<circles.length;x++)
System.out.println(circles[x].getRadius()+"             "+circles[x].getArea());
System.out.println();
System.out.println("总面积为"+sum(circles));
}
}

package Person;
import java.util.Scanner;
public class PersonEmplyee {

public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner input = new Scanner(System.in);
String name1 = input.nextLine();
String address1 = input.nextLine();//想要知道怎么通过空格来读取
String phone1 = input.nextLine();
String email1 = input.nextLine();

Person person = new Person(name1,address1,phone1,email1);

String name2 = input.nextLine();
String address2 = input.nextLine();
String phone2 = input.nextLine();
String email2 = input.nextLine();
String office2 = input.nextLine();
int salary2 = input.nextInt();

Employee employee = new Employee(name2,address2,phone2,email2,office2,salary2);

String name3 = input.nextLine();
String address3 =input.nextLine();
String phone3 = input.nextLine();
String email3 = input.nextLine();
String office3 = input.nextLine();
int salary3 = input.nextInt();
int work3 = input.nextInt();
String title3 = input.nextLine();

Faculty faculty = new Faculty(name3,address3,phone3,email3,office3,salary3,work3,title3);

person.toString();
employee.toString();
faculty.toString();
}

}
class Person{
private String name,address,phone,email;
Person(){}
Person(String name,String address,String phone,String email){
this.name = name;
this.address = address;
this.phone = phone;
this.email =email;
}
public String toString() {
System.out.println("姓名"+this.name);
System.out.println("地址"+this.address);
System.out.println("电话号码"+this.phone);
System.out.println("电子邮件"+this.email);

return "skdjf";
}
}

class Employee extends Person{
private String office;
private int salary;
Employee(){}
Employee(String name,String address,String phone,String email,String office,int salary){
super(name,address,phone,email);//调用父类的构造方法
this.office = office;
this.salary = salary;
}
public String toString() {
super.toString();//使用super调用父类的方法
System.out.println("办公室"+this.office);
System.out.println("工资"+this.salary);

System.out.println();
return "aksjfd";
}
}

class Faculty extends Employee {
public int TEACHINGASSISTANT = 1;
public int LECTERER = 2;
public int ASSOCIATE = 4;
public int PROFESSOR = 4;
private int workingDayAndTime;
private String title;

Faculty(){}
Faculty(String name,String address,String phone,String email,String office,int salary,int workingDayAndTime,String title){
super(name,address,phone,email,office,salary);
this.workingDayAndTime = workingDayAndTime;
this.title = title;
}
public String toString () {
super.toString();
System.out.println("办公时间"+this.workingDayAndTime);
System.out.println("职称"+this.title);
return "sldfj";
}

}