C++ white space string - c++

Question

I'm brand new into C++. I would like to know, why my code is not working.
I've got string called Response.
If the response begins with y/Y it should proceed. However I would like to proceed when the user types " y"/" Y" (the white space) as well.
Here is my code.
Thanks in advance!
bool AskToPlayAgain()
{
std::cout << "Would you like to play again? Yes/N";
std::string Response = "";
std::getline(std::cin, Response);
return (Response[0] == 'y') || (Response[0] == 'Y' +) ||(Response[0] == ' y' +) (Response[0] == ' Y' +);
std::cout << std::endl;
}

Answer 1

With Response[0] you access the first character of the string. You can compare that, as you do, with a character constant, such as 'y'. However, if you want to allow the leading space, this is no longer a single character, so your comparison Response[0] == ' y' cannot work.
Here is a version which allows as many space characters as needed, and then y or Y (C++11 version):
for (auto c:Response)
if (c!=' ')
return (c=='y') || (c=='Y');
//string is only spaces
return false;

Answer 2

You can traverse string Response and ignore white spaces(I am considering Tabs and Spaces in this case) while traversing.
If first character is non white space then you can break the loop I am using flag yes in this case.
bool AskToPlayAgain()
{
std::cout << "Would you like to play again? Yes/N";
auto Response="";
std::getline(std::cin, Response);
auto yes = false;
auto itr = Response.begin();
while(itr != Response.end())
{
if(*itr != ' ' && *itr !='\t')
{
yes = (*itr == 'y' || *itr =='Y') ;
break;
}
++itr;
}
return yes;
}

Answer 3

You can remove the spaces from the response and check with only 'Y'/'y'.
bool AskToPlayAgain()
{
std::cout << "Would you like to play again? Yes/N";
std::string Response = "";
std::getline(std::cin, Response);
Response.erase(remove(Response.begin(), Response.end(), ' '), Response.end());
return (Response[0] == 'y') || (Response[0] == 'Y');
}

Answer 4

Use a loop to check each of your character inside the input string...
For example, like this, usage of the usual loop which can be used in all versions of C++ (You can use the range based for loop like in the above answer...):
bool ask_to_play_again(std::string Response)
{
for (auto i = 0; i < Response.size(); i++)
if (!isspace(Response[i])) // Is not a whitespace character
return tolower(Response[i]) == 'y';
return false; // If the user enters invalid input, close the game anyway...
}
Kind regards,
Ruks.

Answer 5

Maybe you can use std::find function to resolve the problem.
bool AskToPlayAgain()
{
std::cout << "Would you like to play again? Yes/N";
std::string Response = "";
std::getline(std::cin, Response);
auto pos1 = Response.find("Y");
auto pos2 = Response.find("y");
if (pos1 != std::string::npos || pos2 != std::string::npos)
return true;
return false;
}