Java入门——day46

1.Dog类

定义一个Dog 类，包含了age,weight 等属性，以及对这些属性操作的方法，实现并测试这个类。

//Dog类
public class Dog {
    private int age;     //年龄
    private int weight;  //体重
    public Dog() {
    }
    public Dog(int age, int weight) {
        this.age = age;
        this.weight = weight;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public int getWeight() {
        return weight;
    }
    public void setWeight(int weight) {
        this.weight = weight;
    }
    public static void main(String[] args) {
        Dog kiki=new Dog(5,12);
        System.out.println("Dog name：kiki");
        System.out.println("age："+kiki.getAge());
        System.out.println("weight："+kiki.getWeight());
    }
}

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  2.Rectangle类

设计并测试一个名为Rectangle的矩形类，其属性为矩形的左下角与右上角两个点的坐标，根据坐标能计算矩形的面积。

import java.util.Scanner;
//点类
class Point{
    private float x; //横坐标
    private float y; //纵坐标
    public Point(){
    }
    public Point(float x,float y) {
        this.x=x;
        this.y=y;
    }
    public float getX() {
        return x;
    }
    public float getY() {
        return y;
    }
}
//矩形类
public class Rectangle {
    private Point p1=new Point(); //矩形左下角点
    private Point p2=new Point(); //矩形右上角点
    public Rectangle() {
    }
    public Rectangle(Point p1, Point p2) {
        this.p1 = p1;
        this.p2 = p2;
    }
    //计算矩形面积
    public void Area() {
        double s;
        s=(double)Math.abs((p2.getX()-p1.getX())*(p2.getY()-p1.getY()));
        System.out.println(s);
    }
    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        float a,b,c,d;
        System.out.print("请输入矩形左下角点的坐标：");
        a=in.nextFloat();
        b=in.nextFloat();
        System.out.print("请输入矩形右上角点的坐标：");
        c=in.nextFloat();
        d=in.nextFloat();
        Point p1=new Point(a,b);
        Point p2=new Point(c,d);
        Rectangle r=new Rectangle(p1,p2);
        System.out.print("此矩形面积：");
        r.Area();
    }
}

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3.人员类

设计一个用于人事管理的“人员”类。由于考虑到通用性，这里只抽象出所有类型人员都具有的属性：编号、性别、出生日期、身份证号等。其中“出生日期”声明为一个“日期”类内嵌子对象。用成员函数实现对人员信息的录入和显示。

import java.util.Scanner;
//日期类
class Date{
    private int year;
    private int month;
    private int day;
    public Date() {
    }
    public Date(int year,int month,int day) {
        this.year=year;
        this.month=month;
        this.day=day;
    }
    public void set() {
        Scanner in=new Scanner(System.in);
        year=in.nextInt();
        month=in.nextInt();
        day=in.nextInt();
    }
    public void display() {
        System.out.println(year+"."+month+"."+day);
    }
}
//人员类
public class People {
    private int num; //编号
    private String sex; //性别
    private Date date=new Date(); //出生日期
    private String ID; //身份证号
    public People() {
    }
    public People(int num, String sex, Date date, String iD) {
        super();
        this.num = num;
        this.sex = sex;
        this.date = date;
        ID = iD;
    }
    public void input() {
        Scanner in=new Scanner(System.in);
        System.out.println("请输入人员信息：");
        System.out.print("编号：");
        num=in.nextInt();
        System.out.print("性别：");
        sex=in.next();
        System.out.print("出生日期：");
        date.set();
        System.out.print("身份证号：");
        ID=in.next();
    }
    public void output() {
        System.out.println("编号："+num);
        System.out.println("性别："+sex);
        System.out.println("出生日期：");
        date.display();
        System.out.println("身份证号："+ID);
    }
    public static void main(String[] args) {
        People p=new People();
        p.input();
        p.output();
    }
}

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4.矩形类

定义并实现一个矩形类，有厂、宽两个属性，由成员函数计算矩形的面积。

import java.util.Scanner;
//矩形类
public class Rectangle {
    private int length; //矩形的长
    private int width;  //矩形的宽
    public Rectangle() {
    }
    public Rectangle(int length, int width) {
        this.length = length;
        this.width = width;
    }
    //计算矩形的面积
    public void area() {
        int s;
        s=length*width;
        System.out.println("矩形面积："+s);
    }
    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        int a,b;
        System.out.print("请输入矩形的长和宽：");
        a=in.nextInt();
        b=in.nextInt();
        Rectangle r=new Rectangle(a,b);
        r.area();
    }
}

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5.数据类型类

定义一个DataType（数据类型）类，能处理包含字符型、整型、浮点型3种类型的数据，给出其构造函数。

//数据类型
public class DataType {
    private char s;  //字符型
    private int a;   //整型
    private float b; //浮点型
    public DataType() {
    }
    public DataType(char s, int a, float b) {
        this.s = s;
        this.a = a;
        this.b = b;
    }
    public void display() {
        System.out.println("字符型："+s);
        System.out.println("整型："+a);
        System.out.println("浮点型："+b);
    }
    public static void main(String[] args) {
        DataType p=new DataType('m',10,125.2f);
        p.display();
    }
}

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6.Circle类

定义一个Circle 类，有数据成员radius（半径），成员函数getArea()，计算圆的面积，构造一个Circle的对象进行测试。

import java.util.Scanner;
//Circle类
public class Circle {
    private double radius; //半径
    public Circle() {
    }
    public Circle(double radius) {
        this.radius = radius;
    }
    public void getArea() {
        double s;
        s=3.1415926*radius*radius;
        System.out.printf("面积：%-10f",s);
    }
    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        double r;
        System.out.print("半径：");
        r=in.nextDouble();
        Circle c=new Circle(r);
        c.getArea();
    }
}

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7.树类

定义一个Tree（树）类，有成员ages（树龄），成员函数grow(int years)对ages加上years，age()显示Tree对象的ages的值。

import java.util.Scanner;
//Tree类
public class Tree {
    private int ages; //树龄
    public Tree() {
    }
    public Tree(int ages) {
        this.ages=ages;
    }
    //增加生长年数
    public void grow(int years) {
        ages+=years;
    }
    //显示树龄
    public void age() {
        System.out.println("树龄："+ages);
    }
    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        int a,b;
        System.out.print("请输入原有树龄：");
        a=in.nextInt();
        System.out.print("请输入生长的年数：");
        b=in.nextInt();
        Tree t=new Tree(a);
        t.grow(b);
        t.age();
    }
}

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8.CPU类

编写一个名为CPU的类，描述一个CPU的以下信息：时钟频率，最大不会超过3000MHZ；字长，可以是32位或64位；核数，可以是单核、双核或四核；是否支持超线程。各项信息要求使用位域来表示。

//CPU类
enum Word{
    bit32,bit64
}
enum Heshu{
    one,two,four
}
enum Yes_no{
    yes,no
}
public class CPU {
    private int fre;
    private Word wd;
    private Heshu hu;
    private Yes_no yo;
    public CPU() {
    }
    public CPU(int fre, Word wd, Heshu hu, Yes_no yo) {
        this.fre = fre;
        this.wd = wd;
        this.hu = hu;
        this.yo = yo;
    }
    public void show() {
        System.out.println("时钟频率："+fre);
        System.out.print("字长：");
        switch(wd) {
        case bit32:System.out.println("32位");break;
        case bit64:System.out.println("64位");break;
        }
        System.out.print("核数：");
        switch(hu) {
        case one:System.out.println("单核");break;
        case two:System.out.println("双核");break;
        case four:System.out.println("四核");break;
        }
        System.out.print("是否支持超线程：");
        switch(yo) {
        case yes:System.out.println("是");break;
        case no:System.out.println("否");break;
        }
    }
    public static void main(String[] args) {
        CPU c=new CPU(300000,Word.bit64,Heshu.two,Yes_no.yes);
        c.show();
    }
}