cppreference.com > C/C++ Keywords > bool bool The keyword bool is used to declare Boolean logic variables; that is, variables which can be either true or false. For example, the following code declares a boolean variable called done, initializes it to false, and then loops until that variable is set to true.
       bool done = false;
       while( !done ) {
       ...
       }
Also see the data types page. Related topics: char double false float int long short signed true unsigned wchar_t