C++ Key Detection

[anagiotis567]

So I was wondering how to detect a pressed key instead of the user having to press enter evey time an input is needed.The following code is just a simple up to 5-digit calculator i made.It's not perfect but its something.

#include <iostream>int main(){//all variableschar Selection1;char Selection2;char Selection3;char Selection4;char Selection5;char Selection6;char Selection7;char Selection8;char Selection9;char Selection10;char Selection1d;char Selection2d;char Selection3d;float Number1;float Number2;float Number3;float Number4;float Number5;float Number6;float Number7;float Number8;float Number9;float Number10;double Number1d;double Number2d;double Number3d;double Number4d;double Number5d;double Number6d;double Number7d;double Number8d;double Number9d;double Number10d;float result;    std::cout<<"__________Calculator_________\n";    std::cout<<"Welcome To My New Calculator.\n";    std::cout<<"1     Addition\n"<<"2     Subtraction\n"<<"3     Division\n"<<"4     Multiplication\n\n";    std::cin>>Selection1;    if(Selection1 == '1')    {        std::cout<<"You Selected Addition.\n";        std::cout<<"Please Enter The First Number.\n";        std::cin>>Number1;        std::cout<<"Please Enter The Second Number.\n";        std::cin>>Number2;        std::cout<<"Do You Want To Add Another Number?\n";        std::cout<<"Please Answer Y or N.\n";        std::cin>>Selection2;        if(Selection2 == 'Y' or Selection2 == 'y')        {            std::cout<<"Please Enter The Third Number.\n";            std::cin>>Number3;            result = Number1 + Number2 + Number3;            std::cout<<"Do You Want To Add Another Number?\n";            std::cout<<"Please Answer Y or N.\n";            std::cin>>Selection3;        }        else if(Selection2 == 'N' or Selection2 == 'n')        {            result=Number1+Number2;            std::cout<< Number1<<'+'<< Number2<<'=';            std::cout<< result;            return 0;        }        if(Selection3 == 'Y' or Selection3 == 'y')            {            std::cout<<"Please Enter The Fourth Number\n";            std::cin>>Number4;            std::cout<<"Do You Want To Add Another Number?\n";            std::cout<<"Please Answer Y or N.\n";            std::cin>>Selection4;            }            else if (Selection3 == 'N' or Selection3 == 'n')        {            result = Number1 + Number2 + Number3;            std::cout<< Number1<<'+'<< Number2<<'+'<< Number3<<'=';            std::cout<<result;            return 0;        }         if(Selection4 == 'Y' or Selection4 == 'y' )         {            std::cin>>Number5;            result = Number1 + Number2 + Number3 + Number4 + Number5;            std::cout<< Number1<<'+'<< Number2<<'+'<< Number3<<'+'<<Number4<<'+'<<Number5<<'=';            std::cout<<result;            return 0;         }    if(Selection4 == 'N' or Selection4 == 'n' )            {            result = Number1 + Number2 + Number3 + Number4;            std::cout<< Number1<<'+'<< Number2<<'+'<< Number3<<'=';            std::cout<<result;            return 0;            }        }    else if(Selection1 == '2')    {        std::cout<<"You Selected Subtraction.\n";        std::cout<<"Please Enter The First Number.\n";        std::cin>>Number6;        std::cout<<"Please Enter The Second Number.\n";        std::cin>>Number7;        std::cout<<"Do You Want To Subtract Another Number?\n";        std::cout<<"Please Answer Y or N.\n";        std::cin>>Selection5;        if(Selection5 == 'Y' or Selection5 == 'y')        {            std::cout<<"Please Enter The Third Number.\n";            std::cin>>Number8;            result = Number6 - Number7 - Number8;            std::cout<<"Do You Want To Subtract Another Number?\n";            std::cout<<"Please Answer Y or N.\n";            std::cin>>Selection6;        }        else if(Selection5 == 'N' or Selection5 == 'n')        {            result=Number6 - Number7;            std::cout<< Number6<<'-'<< Number7<<'=';            std::cout<< result;            return 0;        }        if(Selection6 == 'Y' or Selection6 == 'y')            {            std::cout<<"Please Enter The Fourth Number\n";            std::cin>>Number9;            std::cout<<"Do You Want To Subtract Another Number?\n";            std::cout<<"Please Answer Y or N."<<std::endl;            std::cin>>Selection7;            }            else if (Selection6 == 'N' or Selection6 == 'n')        {            result=Number6 - Number7 - Number8 - Number9;            std::cout<< Number6<<'-'<< Number7<<'-'<< Number8<<'-'<< Number9<<'=';            std::cout<<result;            return 0;        }         if(Selection7 == 'Y' or Selection7 == 'y')         {            std::cin>>Number10;            result = Number6 - Number7 - Number8 - Number9 - Number10;            std::cout<< Number6<<'-'<< Number7<<'-'<< Number8<<'-'<<Number9<<'-'<<Number10<<'=';            std::cout<<result;            return 0;         }    else if(Selection7 == 'N' or Selection7 == 'n')         {            result = Number6 - Number7 - Number8 - Number9;            std::cout<< Number6<<'-'<< Number7<<'-'<< Number8<< Number9<<'=';            std::cout<<result;            return 0;            }    }    else if(Selection1 == '3')    {        std::cout<<"You Selected Division."<<std::endl;        std::cout<<"Please Enter The First Number.\n";        std::cin>>Number1d;        std::cout<<"Please Enter The Second Number.\n";        std::cin>>Number2d;        std::cout<<"Do You Want To Divide Another Number?\n";        std::cout<<"Please Answer Y or N.\n";        std::cin>>Selection8;        if(Selection8 == 'Y' or Selection8 == 'y')        {            std::cout<<"Please Enter The Third Number.\n";            std::cin>>Number3d;            result=Number1d / Number2d / Number3d;            std::cout<<"Do You Want To Divide Another Number?\n";            std::cout<<"Please Answer Y or N.\n";            std::cin>>Selection9;        }    else if(Selection8 == 'N' or Selection8 == 'n')    {            result = Number1d / Number2d;            std::cout<< Number1d<<'/'<< Number2d<<'=';            std::cout<<result;            return 0;    }    if(Selection9 == 'Y' or Selection9 == 'y')    {        std::cout<<"Please Enter The Fourth Number.\n";        std::cin>>Number4d;        result=Number1d / Number2d / Number3d / Number4d;        std::cout<<result;        std::cout<<"Do You Want To Divide Another Number?\n";        std::cout<<"Please Answer Y or N.\n";        std::cin>>Selection10;    }    else if(Selection9 == 'N' or Selection9 == 'n')    {        result=Number1d / Number2d / Number3d;        std::cout<< Number1d<<'/'<< Number2d<<'/'<<Number3d<<'=';        std::cout<<result;        return 0;    } if(Selection10 == 'Y' or Selection10 == 'y')  {     std::cout<<"Please Enter The Fifth Number.\n";     std::cin>>Number5d;     result=Number1d/Number2d/Number3d/Number4d/Number5d;     std::cout<<Number1d<<'/'<< Number2d<<'/'<<Number3<<'/'<<Number4d<<'/'<<Number5d;     std::cout<<result;     return 0;  } else if(Selection10 == 'N' or Selection10 == 'n')   {        result=Number1d/Number2d/Number3d/Number4d;        std::cout<< Number1d<<'/'<< Number2d<<'/'<<Number3d<<'/'<<Number4d<<'=';        std::cout<<result;        return 0;   }  }    else if (Selection1 == '4')    {        std::cout<<"You Selected Multiplication.\n";        std::cout<<"Please Enter The First Number.\n";        std::cin>>Number6d;        std::cout<<"Please Enter The Second Number.\n";        std::cin>>Number7d;        std::cout<<"Do You Want To Multiply Another Number?\n";        std::cout<<"Please Answer Y or N.\n";        std::cin>>Selection1d;        if(Selection1d == 'Y' or Selection1d == 'y')        {            std::cout<<"Please Enter The Third Number.\n";            std::cin>>Number8d;            result=Number6d * Number7d * Number8d;            std::cout<<"Do You Want To Multiply Another Number?\n";            std::cout<<"Please Answer Y or N.\n";            std::cin>>Selection2d;        }    else if(Selection1d == 'N' or Selection1d == 'n')    {            result = Number6d * Number7d;            std::cout<< Number6d<<'*'<< Number7d<<'=';            std::cout<<result;            return 0;    }    if(Selection2d == 'Y' or Selection2d == 'y')    {        std::cout<<"Please Enter The Fourth Number.\n";        std::cin>>Number9d;        std::cout<<"Do You Want To Multiply Another Number?\n";        std::cout<<"Please Answer Y or N.\n";        std::cin>>Selection3d;    }    else if(Selection2d == 'N' or Selection2d == 'n')    {        result=Number6d * Number7d * Number8d;        std::cout<<Number6d<<'*'<<Number7d<<'*'<<Number8d<<'=';        std::cout<<result;        return 0;    } if(Selection3d == 'Y' or Selection3d == 'y')  {     std::cout<<"Please Enter The Fifth Number.\n";     std::cin>>Number10d;     result=Number6d * Number7d * Number8d * Number9d * Number10d;     std::cout<<Number6d<<'*'<< Number7d<<'*'<<Number8d<<'*'<<Number9d<<'*'<<Number10d<<'=';     std::cout<<result;     return 0;  } else if(Selection3d == 'N' or Selection3d == 'n')   {        result=Number6d * Number7d * Number8d * Number9d;        std::cout<< Number6d<<'*'<< Number7d<<'*'<<Number8d<<'*'<<Number9d<<'=';        std::cout<<result;        return 0;   }  } }

[Dobbsjr]

 

So I was wondering how to detect a pressed key instead of the user having to press enter evey time an input is needed.The following code is just a simple up to 5-digit calculator i made.It's not perfect but its something.

I'm confused. You want user input without the user inputing anything?

[Dobbsjr]

Also maybe #include <string>?

[topsu]

Try kbhit() and getch();

[Nineshadow]

I don't really understand why you would want to do that, but there you go:

conio.h has a getch() function that does exactly what you want.

#include <conio.h>#include <iostream>int main(){    char key=' ';    key = getch();    std::cout << key;    return 0;}

That is really simple and easy to handle. You could also use Events, but that's a lot more complicated.You might also want to check if the user actually inputs anything with kbhit().

 

Also, why so many variables. Jeez D:.

@anagiotis567 follow your topics.

[Oskar94a]

you should use arrays and some loops and your code will be much shorter!

[trag1c]

If your on Windows you could use Win32 with your wndproc registering key up and key down messages.

[Zeruel]

I would just suggest using the Ncurses library...

 

http://tldp.org/HOWTO/NCURSES-Programming-HOWTO/index.html

 

Use that guide

 

and here is the Windows version

 

http://pdcurses.sourceforge.net/