我的程序中的一个值被错误地计算，即使支持的数学是正确的

Question

在我的课程的一个模块中，我们正在编写一个程序，要求输入班名、成绩和学分数量。在一定数量的类的末尾，它要求我们使用setprecision(2)计算GPA到2个小数点。我所有的程序函数，除了它计算的GPA是3.00而不是3.14。我的totalPoints是22，而totalCredits是7，所以它理所当然地应该是3.14。你能理解为什么我会得到3.00吗？任何帮助都是非常感谢的，因为我对此非常陌生。

#include iostream
#include iomanip
#include string
//I took out the < and > because it made the words disappear

using namespace std;

int main(){
    cout<< std::fixed << std::setprecision(2);

    int totalCredits = 0;
    int gradePoints = 0;

    string courseName;
    cout<<"Enter a course name: ";
    getline (cin, courseName);
    cout<<courseName <<endl;

    int credits;
    cout<<"Enter number of credits: ";
    cin>>credits;
    cout<<credits <<endl;
    totalCredits = totalCredits + credits;

    string grade;
    cout<<"Enter your grade (A, B, C, D, F): ";
    cin>>grade;
    cout<<grade <<endl;

    if (grade == "A"){
      gradePoints = gradePoints + (4.00 * credits);
    }
    else if (grade == "B"){
      gradePoints = gradePoints + (3.00 * credits);
    }
    else if (grade == "C"){
      gradePoints = gradePoints + (2.00 * credits);
    }
    else if (grade == "D"){
      gradePoints = gradePoints + (1.00 * credits);
    }


    string answer;
    cout<<"Continue ('Yes' or 'No')? ";
    cin>>answer;
    cout<<answer <<endl;

    while (answer == "Yes"){
      cout<<"Enter a course name: ";
      cin.ignore();
      getline (cin, courseName);
      cout<<courseName <<endl;

      cout<<"Enter number of credits: ";
      cin>>credits;
      cout<<credits <<endl;
      totalCredits = totalCredits + credits;

      cout<<"Enter your grade (A, B, C, D, F): ";
      cin>>grade;
      cout<<grade <<endl;

      if (grade == "A"){
         gradePoints = gradePoints + (4.00 * credits);
      }
      else if (grade == "B"){
         gradePoints = gradePoints + (3.00 * credits);
      }
      else if (grade == "C"){
         gradePoints = gradePoints + (2.00 * credits);
      }
      else if (grade == "D"){
         gradePoints = gradePoints + (1.00 * credits);
      }


      cout<<"Continue ('Yes' or 'No')? ";
      cin>>answer;
      cout<<answer <<endl;
    }

    cout<<"Total grade points: " <<gradePoints <<endl;
    cout<<"Total credits attempted: " <<totalCredits <<endl;

   float gpa = 0;
   gpa = gradePoints/totalCredits;
   cout<<"Your GPA is " <<gpa <<endl;



   return 0;  
}

Answer 1

整型除以整型得到整型。通过在除法语句的变量名前添加(double)来转换其中之一。

其他注意事项：

，

• ，你几乎重复了整个程序，只是为了确保它能执行一次。你可以简单地将答案设置为“是”，你就知道它会执行。
• cin <<变得非常挑剔。more info，通常你最好使用getLine()并根据需要进行解析。(可能是家庭作业的过度杀伤力...)本例中的quickfix使用ignore()清除流，并使用clear()重置流。示例工作程序here.