5月8日打卡

例4-8

题目描述：

使用联合体保存成绩信息，并且输出

代码部分：

#include<string>
#include<iostream>
using namespace std;
class ExamInfo {
private:
    string name;
    enum {
        GRADE,
        PASS,
        PERCENTAGE
    }mode;
    union {
        char grade;
        bool pass;
        int percant;
    };
public:
    ExamInfo(string name,char grade):name(name),mode(GRADE),grade(grade){}
    ExamInfo(string name,bool pass):name(name),mode(PASS),pass(pass){}
    ExamInfo(string name,int percant):name(name),mode(PERCENTAGE),percant(percant){}
    void show()
    {
        cout << name << ":";
        switch (mode) {
        case GRADE:cout << grade;
            break;
        case PASS:cout << (pass ? "PASS" : "FALL");
            break;
        case PERCENTAGE:cout << percant;
            break;
        }
        cout << endl;
    }
};
int main()
{
    ExamInfo couse1("English", 'B');
    ExamInfo couse2("Calculus", 'true');
    ExamInfo couse3("C++Programming", 85);
    couse1.show();
    couse2.show();
    couse3.show();
    return 0;
}

例4-9

题目描述：

设某次体育比赛的结果有四种可能：胜（WIN）、负（LOSE）、平局（TIE）、比赛取消（CANCEL），编写程序输出这四种情况。

分析：1.设计一个枚举类型一次输出四种可能的结果。

代码部分：

#include<iostream>
using namespace std;
enum GameResult{WIN,LOSE,TIE,CANCEL};
int main()
{
    GameResult result;
    enum GameResult omit = CANCEL;
    for (int count = WIN; count <= CANCEL; count++)
    {
        result = GameResult(count);
        if (result = omit)
            cout << "The game was cancelled" << endl;
        else {
            cout << "The game was cancelled" << endl;
            if (result == WIN)
            {
                cout << "and we won!";
        }
            if (result == LOSE)
            {
                cout << "and we lost.";
            }
            cout << endl;
        }
        return 0;
    }
}