How to check if a std::string is set or not?

Question

If using a char*, I can initialize it to NULL and later check if it is set by doing a comparison. How to do the same thing for a std::string

Answer 1

You can't; at least not the same way you can test whether a pointer is NULL.

A std::string object is always initialized and always contains a string; its contents by default are an empty string ("").

You can test for emptiness (using s.size() == 0 or s.empty()).