Question

I know that when writing code like std::cin >> some_var; , where some_var is a string variable, only the first word that was inputted will be stored in some_var. But I do not understand why std::cout << "something here"; does not only output “something”. Am I missing something?

Answer 1

When reading input using cin >> some_var, the delimiter is space by default (you can change this though), while when printing, cout prints till its find \0 which is end of the string.

If you want to read till it finds \0 in the input stream, then you’ve to write this:

std::getline(std::cin, some_var, '\0');

You can give any other character as delimiter as third argument of std::getline function.

Note that there is a member function with same name getline which is slightly different than the one I used above which is a free standalone function.

Compare:

• std::getline – free standalone function. An overloaded function is also available.
• istream::getline – member function of std::istream

I used the first one.