How to cin Space in c++?

Question

Say we have a code:

int main()
{
   char a[10];
   for(int i = 0; i < 10; i++)
   {
       cin>>a[i];
       if(a[i] == ' ')
          cout<<"It is a space!!!"<<endl;
   }
   return 0;
}

How to cin a Space symbol from standard input? If you write space, program ignores! :( Is there any combination of symbols (e.g. '\s' or something like this) that means "Space" that I can use from standard input for my code?

Answer 1

Use cin.get() to read the next character.

However, for this problem, it is very inefficient to read a character at a time. Use the istream::read() instead.

int main()
{
   char a[10];
   cin.read(a, sizeof(a));
   for(int i = 0; i < 10; i++)
   {
       if(a[i] == ' ')
          cout<<"It is a space!!!"<<<endl;
   }
   return 0;
}

And use == to check equality, not =.

Answer 2

Using cin's >> operator will drop leading whitespace and stop input at the first trailing whitespace. To grab an entire line of input, including spaces, try cin.getline(). To grab one character at a time, you can use cin.get().

Answer 3

#include <iostream>
#include <string>

int main()
{
   std::string a;
   std::getline(std::cin,a);
   for(std::string::size_type i = 0; i < a.size(); ++i)
   {
       if(a[i] == ' ')
          std::cout<<"It is a space!!!"<<std::endl;
   }
   return 0;
}

Answer 4

It skips all whitespace (spaces, tabs, new lines, etc.) by default. You can either change its behavior, or use a slightly different mechanism. To change its behavior, use the manipulator noskipws, as follows:

 cin >> noskipws >> a[i];

But, since you seem like you want to look at the individual characters, I'd suggest using get, like this prior to your loop

 cin.get( a, n );

Note: get will stop retrieving chars from the stream if it either finds a newline char (\n) or after n-1 chars. It stops early so that it can append the null character (\0) to the array. You can read more about the istream interface here.