Question

我能够输入第一个学生，但是，一旦我请求第二个学生的输入，它就不接受：getline(cin, s2)到getline(cin,s10)。您能否帮我理解错误的位置或输出与s1 / GPA1格式不同的原因？

这是我的代码：

#include <iostream>
#include <string>
#include <iomanip>
using namespace std;

int main()
{
    //Welcome 
    cout << "Welcome to your personal GPA Calculator! \n" << endl;

    float GPA1, GPA2, GPA3, GPA4, GPA5, GPA6, GPA7, GPA8, GPA9, GPA10 = 0;
    string s1, s2, s3, s4, s5, s6, s7, s8, s9, s10;



    //Requesting User Input
    cout << "Student One| Please enter your Last Name, First Name: " << endl;
    getline(cin, s1);
    cout << "What is your current GPA: " << endl;
    cin >> GPA1;
    cout << endl;

    cout << "Student Two| Please enter your Last Name, First Name: " << endl;
    getline(cin, s2); 
    cout << "What is your current GPA: " << endl;
    cin >> GPA2;
    cout << endl;

    cout << "Student Three| Please enter your Last Name, First Name: " << endl;
    getline(cin, s3); 
    cout << "What is your current GPA: " << endl;
    cin >> GPA3;
    cout << endl;

    cout << "Student Four| Please enter your Last Name, First Name: " << endl;
    getline(cin, s4);
    cout << "What is your current GPA: " << endl;
    cin >> GPA4;
    cout << endl;

    cout << "Student Five| Please enter your Last Name, First: " << endl;
    getline(cin, s5);
    cout << "What is your current GPA: " << endl;
    cin >> GPA5;
    cout << endl;

    cout << "Student Six| Please enter your Last Name, First Name: " << endl;
    getline(cin, s6);
    cout << "What is your current GPA: " << endl;
    cin >> GPA6;
    cout << endl;

    cout << "Student Seven| Please enter your Last Name, First Name: " << endl;
    getline(cin, s7);
    cout << "What is your current GPA: " << endl;
    cin >> GPA7;
    cout << endl;

    cout << "Student Eight| Please enter your Last Name, First Name: " << endl;
    getline(cin, s8);
    cout << "What is your current GPA: " << endl;
    cin >> GPA8;
    cout << endl;

    cout << "Student Nine| Please enter your Last Name, First Name: " << endl;
    getline(cin, s9);
    cout << "What is your current GPA: " << endl;
    cin >> GPA9;
    cout << endl;

    cout << "Student Ten| Please enter your Last Name, First Name: " << endl;
    getline(cin, s10);
    cout << "What is your current GPA: " << endl;
    cin >> GPA10;
    cout << endl;

    //Store in Tabular Format
    cout << ("Student Name| \t\t |Student GPA Value \n");
    cout << ("____________________________________________\n");
    std::cout << s1 << "\t\t  " << std::setprecision(2) << std::fixed << GPA1 << endl;
    std::cout << s2 << "\t\t  " << std::setprecision(2) << std::fixed << GPA2 << endl;
    std::cout << s3 << "\t\t  " << std::setprecision(2) << std::fixed << GPA3 << endl;
    std::cout << s4 << "\t\t  " << std::setprecision(2) << std::fixed << GPA4 << endl;
    std::cout << s5 << "\t\t  " << std::setprecision(2) << std::fixed << GPA5 << endl;
    std::cout << s6 << "\t\t  " << std::setprecision(2) << std::fixed << GPA6 << endl;
    std::cout << s7 << "\t\t  " << std::setprecision(2) << std::fixed << GPA7 << endl;
    std::cout << s8 << "\t\t  " << std::setprecision(2) << std::fixed << GPA8 << endl;
    std::cout << s9 << "\t\t  " << std::setprecision(2) << std::fixed << GPA9 << endl;
    std::cout << s10 << "\t\t  " << std::setprecision(2) << std::fixed << GPA10 << endl;

    return (0);

}

Answer 1

当你混合使用cin和getline时，你必须要小心（cin，＆＃34; string＆＃34;）。 Cin将忽略任何空格或行，而getline则不会。发生的事情是，在您输入第一个学生的GPA之后，换行符存储在缓冲区中并被转移到自动输入的getline。尝试在每个cin＆gt;＆gt;之后使用cin.ignore（） GPA。

Answer 2

您通常不想直接使用cin读取数字以进行交互式使用。它并没有很好地适应新行 - 将新行留给下一个条目。在这种情况下，您将获得人员2的空白名称。

试试这个：

string temp;


//Requesting User Input
cout << "Student One| Please enter your Last Name, First Name: " << endl;
getline(cin, s1);
cout << "What is your current GPA: " << endl;

getline(cin, temp);
GPA1 = strtof(temp.c_str(), 0);
cout << endl;

10个学生输入的C ++ GPA Trunc

2 个答案: