Question:
Is there a built-in or default string class in C++ or do I have to create my own? If so, what file can I look in to see the definition of the class?

Answer:
C++ provides the standard class template std::string for handling and manipulating chars in a safe, efficient, object-oriented, and standardized way. You should #include the header in order to use this class and its member functions. Note that it’s declared in namespace STD, so you will need to use the fully-qualified name std::string. Alternatively, you can use an appropriate using-declaration or a using-directive.