C++ 嵌套循环没有给我任何值

Question

所以这个嵌套循环应该为每个练习生成 10 个随机分数 用户输入的学生。生成分数后，必须将它们全部相加并找到平均分数。但是，当我运行程序时，它没有给我任何值。代码如下：

int progExAvg, progExScore, studentAmt;
int counter = 0;
int progExTotal = 0;

srand(time(0));

cout << "Please enter how many students do you have in your class: ";
cin >> studentAmt;
cin.sync();

while (counter < studentAmt)
{
    for(int i = 0; i < 10; i++)
    {
        progExScore = rand() % 100 + 1;
        progExTotal = progExTotal + progExScore;
    }

    progExAvg = progExTotal / 10;



}
cout << progExAvg << endl;
return 0;

Answer 1

你永远不会增加counter，所以它总是小于studentAmt

while (counter < studentAmt)
{
    for(int i = 0; i < 10; i++)
    {
        progExScore = rand() % 100 + 1;
        progExTotal = progExTotal + progExScore;
    }

    progExAvg = progExTotal / 10;

    counter++;

}

Answer 2

移动这些声明

int progExTotal = 0;
int progExTotal = 0;

还有这句话

cout << progExAvg << endl;

在while循环中

还有这个声明

int progExScore;

在for循环中

考虑到使用像 10 这样的幻数是个坏主意。最好使用有意义的名称。

你还必须增加变量计数器。例如

const int TOTAL_EXERCISES =  10;

while (counter++ < studentAmt)
{
    int progExTotal = 0;
    int progExTotal = 0;

    for(int i = 0; i < TOTAL_EXERCISES; i++)
    {
        int progExScore = rand() % 100 + 1;
        progExTotal = progExTotal + progExScore;
    }

    progExAvg = progExTotal / TOTAL_EXERCISES;

    cout << progExAvg << endl;
}