c++ - 对我是否需要一个标记值来终止我的 do while 循环以允许多个条目感到困惑

Question

我要使用一个 do while 循环来打印平均成绩和字母成绩，但随后我被要求使用另一个循环来确定多个成绩。

我的问题是我的 do while 循环进入无限循环，我不确定何时需要终止它。

#include <iostream>

using namespace std;

int main()
{
    float avgscore;
    int count;

    cout << "Please enter enter your average score inpercent format. I.E. 95.6%" << endl;
    cin >> avgscore;

    do
    {
        if (avgscore >= 90)
        cout << "Your exam score is: " << avgscore << " Which results in the grade an A!"<<endl;

        else if (avgscore >= 80)
            cout << "Your exam score is: " << avgscore << " Which results in the grade of a B!" << endl;

        else if (avgscore >= 70)
            cout << "Your exam score is: " << avgscore << " Which results in the grade of a C!" << endl;

        else if (avgscore >= 60)
            cout << "Your exam score is: " << avgscore << " Which results in the grade of a D!" << endl;

        else if (avgscore <= 59.9)
            cout << "Your exam score is: " << avgscore << " Which results in the grade of a F!" << endl;
    }
    while (avgscore > 0); //This is my problem here, but i'm not sure what i need here to end it.
    // I need to add another loop here to allow for more than one entry.

    return 0;
}

如有任何帮助，我们将不胜感激!

Answer 1

你可以简单地把下面几行

cout << "Please enter enter your average score inpercent format. I.E. 95.6%" << endl;
cin >> avgscore;

在do-while里面能够通过输入一个值为 <=0 的值来终止循环.

这里的关键思想是您需要能够更改avgscore循环内的值 这样检查条件就会因为false如果你愿意的话。