课后习题4-12

Posted 2023-04-25 Lyh3012648079

定义一个datatype类，能处理包含字符型，整形，浮点型3种类型的数据，给出其构造函数。

 #include <iostream>
 using namespace std;
 
 class DataType
     private:
         char a;
         int n;
         float x;
 enum 
     character,
     integer,
     floating,
  vartype;
     public:
         DataType(char a)
         
             vartype=character;
             this->a=a;
         
         DataType(int n)
         
             vartype=integer;
             this->n=n;
         
         DataType(float x)
         
             vartype=floating;
             this->x=x;
         
         void print()
         
             switch(vartype)
                 case character:
                     cout<<"zifu"<<a<<endl;
                     break;
                 case integer:
                     cout<<"zhengshu"<<n<<endl;
                     break;
                 case floating:
                     cout<<"fudiashu"<<x<<endl;
                     break;
             
         
 ; 
 int main()
 
     DataType a(\'c\'),b(1),c(1.44F);
     a.print();
     b.print();
     c.print();
 

 

课后习题1

  1 package com.ju;
  2 
  3 public class power {
  4     
  5     //颜色
  6     private String yanse;
  7     
  8     //品牌
  9     private String pinpai;
 10     
 11     //电池容量
 12     private double mah;
 13     
 14     //当前容量
 15     private double dqmah;
 16     
 17     //充电
 18     public void chongdian(double dianliang)
 19     {
 20         if (dianliang < 0)
 21         {
 22             System.out.println("请及时充电");
 23         }
 24         else if (this.dqmah + dianliang > this.mah)
 25         {
 26             double bccd = this.mah-this.dqmah;
 27             
 28             this.dqmah = this.mah;
 29             
 30             System.out.println("已充满，请关闭充电电源" +bccd+"毫安");
 31         }
 32         else
 33         {
 34             this.dqmah += dianliang;
 35             System.out.println("这次充了"+dianliang+"毫安");
 36         }
 37     }
 38     private double xiaohao = 0;
 39     
 40     private double xiaohaozl()
 41     {
 42         return this.xiaohaozl();
 43     }
 44     
 45     //使用 消耗电量
 46     public void xiaohaodl(double xiaohaozl,double xiaohao)
 47     {
 48     
 49         if(this.dqmah <=0)
 50         {
 51             System.out.println("电量低，请充电后使用");    
 52             
 53             return;
 54         }
 55         if (xiaohaozl<0 || xiaohao<0)
 56         {
 57             System.out.println("无法使用");
 58         }
 59         if (this.dqmah < 0 )
 60         {
 61             this.dqmah = 0;
 62             
 63             System.out.println("请充电！");
 64         }
 65     }
 66     
 67     public String getYanse() {
 68         return yanse;
 69     }
 70 
 71     public void setYanse(String yanse) {
 72         this.yanse = yanse;
 73     }
 74 
 75     public String getPinpai() {
 76         return pinpai;
 77     }
 78 
 79     public void setPinpai(String pinpai) {
 80         this.pinpai = pinpai;
 81     }
 82 
 83     public double getMah() {
 84         return mah;
 85     }
 86 
 87     public void setMah(double mah) {
 88         this.mah = mah;
 89     }
 90 
 91     public double getDqmah() {
 92         return dqmah;
 93     }
 94 
 95     public void setDqmah(double dqmah) {
 96         this.dqmah = dqmah;
 97     }
 98 
 99     public power(String pinpai, double mah, double dqmah) {
100         super();
101         this.pinpai = pinpai;
102         this.mah = mah;
103         this.dqmah = dqmah;
104     }
105     public static void main(String[]args)
106     {
107         power myMi = new power("小米",20000,500);
108         
109         System.out.println("品牌 = "+ myMi.getPinpai());
110         
111         System.out.println("电量 = "+ myMi.getMah());
112         
113         
114     }
115 
116 }
117 
118 }