JAVA面向对象第一章课后作业

   JAVA面向对象程序设计
  第一章课后作业
0.计算机
package tz1;

public class Calculator {
 int dig1;
 int dig2;
 double dig3;
    String alg;
    public void show() {
     System.out.println(dig3);
    }
  
}
package tz1;

import java.util.Scanner;

public class Calculator1 {
  public static void main(String[] args) {
   Scanner input = new Scanner(System.in);
   Calculator Calculator1 = new Calculator();
   System.out.print("请输入数字：");
   Calculator1.dig1 = input.nextInt();
   System.out.print("请输入+，—，*，/");
   Calculator1.alg = input.next();
   System.out.print("请输入数字：");
   Calculator1.dig2 = input.nextInt();
   switch (Calculator1.alg) {
   case "+":
    Calculator1.dig3=Calculator1.dig1+Calculator1.dig2;
    break;
   case "-":
    Calculator1.dig3=Calculator1.dig1-Calculator1.dig2;
    break;
   case "*":
    Calculator1.dig3=Calculator1.dig1*Calculator1.dig2;
    break;
   case "/":
    Calculator1.dig3=Calculator1.dig1/Calculator1.dig2;
    break;

   default:
    break;
   }
   Calculator1.show();
  }
}

1.编写一个CurrentTime类
package tz1;
public class CurrentTime {
  int year = 2015;
  int month = 5;
  int day = 12;
  int point = 10;
  int part = 11;
  int seconds =00;
  public void show() {
   System.out.println(year+"年"+month+"月"+day +"日"+point+"点"+part+"分"+seconds+"秒");
  }
  }
package tz1;

public class CurrentTime1 {
 public static void main(String[] args) {
  CurrentTime tets = new CurrentTime();
  tets.show(); 
 }
 }

2.改变CurrentTime的时间
package tz1;
public class CurrentTime {
  int year = 2015;
  int month = 5;
  int day = 12;
  int point = 10;
  int part = 11;
  int seconds =00;
  public void show() {
   System.out.println(year+"年"+month+"月"+day +"日"+point+"点"+part+"分"+seconds+"秒");
  }
package tz1;

public class Demo1 {
  public static void main(String[] args) {
   CurrentTime tets = new CurrentTime();
   tets.seconds = 30;
   tets.show();
  }
  }
  }
3.使用类的方法描述计算机
package tz1;

public class Computer {
 String CPU = "英特尔";
 String Motherboard = "Timi TM1703";
 String Display = "三星";
 String HardDisk = "西部数据";
 String Memory = "威刚";
 public void show() {
  System.out.println(CPU+"cpu"+Motherboard+"主板"+Display+"显示器"+HardDisk+"硬盘"+Memory+"内存");
 }

 }
package tz1;

public class Computer1 {
 public static void main(String[] args) {
  Computer out = new Computer();
  out.show();
 }
 }
4.开发游戏
package tz1;

public class Hero {
 String name = "李小侠";
 int Life = 300;
 public void show() {
  System.out.println("我是英雄，我的基本信息如下：");
  System.out.println("姓名:"+name+"生命值:"+Life);
 }
 }
package tz1;

public class Monster {
 String name = "小龟";
 int Life = 300;
 String Type = "潜水类";
 public void show() {
  System.out.println("我是怪物，我的基本信息如下：");
  System.out.println("姓名:"+name+"生命值:"+Life+"类型:"+Type);
 }
 }
package tz1;

public class Weapons {
 String name = "死神镰刀";
 int Attack = 12;
 public void show() {
  System.out.println("我是武器，抢哦的信息如下：");
  System.out.println("武器名:"+name+"攻击力:"+Attack);
 }
 }
package tz1;

public class Game {
 public static void main(String[] args) {
  
 
 Hero hero = new Hero();
 Weapons weapons = new Weapons();
 Monster monster = new Monster();
 hero.show();
 weapons.show();
 monster.show();
 }
 }
1.简述什么是类和对象，以及两者之间的关系
  1.对象是用来描述客观事物的一个实体，有一组属性和方法构成。
  2.类定义了对象将会拥有的特征（属性）和行为（方法）。
  3类和对象的非关系是抽象和具体的关系，类是对象的类型，对象是类的实例。