C++ using cin in a switch statement

c

c++ I am writing a program with a menu. I am using a do while loop and a switch statement to execute the menu. I am calling functions into the different cases. When i call a function that has cin in it my program skips over the cin. How can i get the cin to work in my switch statement?

here is the function for my menu. after researching i tried different formats that aren't working.
case 1, 2, and 5 are not working. 

    void Execute_Main_Menu(Student &Temp, Student List[], int File_Size, ifstream &fin)
    {
        char Choice ;
        ofstream fout ;

        do
        {
            cout << "\n\nWhat would you like to do?  Enter 1-8: " ;
            cin >> Choice ;
            Student Temp ;

            switch(Choice)
            {
            case '1' : 
                {
            File_Size=Read_Data(List, CAP) ;
            Another_Task() ;
            break ;
                }
            case '2' : Open_Output_File(fout) ;
                Print_List_To_File(List, File_Size, fout) ;
                Another_Task() ;
                break ;
            case '3' : Sort_Menu() ;
                Execute_Sort_Menu(List, File_Size) ;
                Another_Task() ;
                break ;
            case '4' : Print_List(List, File_Size) ;
                Another_Task() ;
                break ;
            case '5' : Print_Student(Temp, List, File_Size) ;
                break ;
            case '6' : cout << "F" ;
                break ;
            case '7' : cout << "G" ;
                break ;
            case '8' : cout << "\n\nThank You.  Good Bye." ;
                exit (0) ;
            default : cout << "\nBad Input. Must be 1-8." ;
            }   
        }
            while(Choice != 8);
    }

here are examples of cin in functions i am calling

    bool Open_Output_File(ofstream &fout) 
    {
        string Output ;

        cout << "\nEnter the name of the output file: " ;

        getline(cin, Output) ;
        fout.open(Output.c_str()) ;

        if (fout.fail())
            return false ;
        else
            return true ;
    }   
    void Execute_Sort_Menu(Student List[], int File_Size)
    {
            char Choice ;

        do
        {
        cout << "\nWhat would you like to do?  Enter 1 or 2: " ;
        cin >> Choice ;

            switch(Choice)
            {
            case '1' : Sort_B_Last_Name(List, File_Size) ;
                Print_List(List, File_Size) ;
                break ;
            case '2' : Sort_B_Average(List, File_Size ) ;
                Print_List(List, File_Size) ;
                break ;
            default : cout << "\nYou have to enter the number 1 or the number 2." ;
            }
        }
        while(Choice !='1' && Choice !='2');
    }   
    bool Open_Input_File(ifstream &fin)
    {
        string Input ;

        cout << "Enter the name of the input file: " ;

        getline(cin, Input) ;
        fin.open(Input.c_str()) ;

        if (fin.fail())
            return false ;
        else
            return true ;
    }
    int Read_Data(Student List[], int Size)
    {
        ifstream fin ;
        int     i = 0;

        if (Open_Input_File(fin)== true )
        {
            string Course_Name, Course_Id, Location ;

            getline(fin, Course_Name) ;
            getline(fin, Course_Id) ;
            getline(fin, Location) ;
            Read_Student(List[i], fin);
            while(!fin.eof())
            {
                i++ ;
                if(i == Size)
                {
                    cout << "\nArray is full.\n" ;
                    return (i);
                } 
                Read_Student(List[i], fin);
            }
        }
        else
        {
            cout <<"\nBad File Name. Did not open. Program terminated.\n\n";
            exit(0);
        }
        return (i);
        fin.close() ;
    }

Best Answer

I took your code and cut out the main switch logic: This works. I added a second function with a cin statement, it calls appropriately.

#include <iostream>
using namespace std;


void another_function_with_cin()
{
    char Choice;
    cout << "What should I echo? ";
    cin >> Choice;
    cout << "Echoing: " << Choice << std::endl;
}

void Execute_Main_Menu()
{
    char Choice ;
    do
    {
        cout << "\n\nWhat would you like to do?  Enter 1-8: " ;
        cin >> Choice ;

        switch(Choice)
        {
            case '1' :
            {
                cout << 1 << endl;
                another_function_with_cin();
                break ;
            }
            case '2' :
            {
                cout << 2 << endl;
                another_function_with_cin();
                break;
            }
            case '3' :
            {
                cout << 3 << endl;
                another_function_with_cin();
                break;
            }
            case '4' :
            {
                cout << 4 << endl;
                another_function_with_cin();
                break;
            }
            case '5' :
            {
                cout << 5 << endl;
                another_function_with_cin();
                break;
            }
            case '6' :
            {
                cout << 6 << endl;
                another_function_with_cin();
                break;
            }
            case '7' :
            {
                cout << 7 << endl;
                another_function_with_cin();
                break;
            }
            case '8' :
            {
                cout << 8 << endl;
                another_function_with_cin();
                break;
            }
            default : cout << "\nBad Input. Must be 1-8." ;
        }
    }while(Choice != 8);
}


int main(int argc, char const *argv[])
{
    Execute_Main_Menu();
    return 0;
}

I suspect it is how you are using getline. You could try using cin for strings too...

std::string filename;
cin >> filename;

Also, when you open a file, if it succeeds, you should remember to close it.

std::ofstream fout(filename.c_str());
if(fout.is_open)
{
    fout.close();
}
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