Why sizeof() of a string variable always return the same number even when content changes?

Question

This is a rather simple problem but is pretty confusing.

string R = \"hhhh\" ;
cout<< sizeof( R )<

OUTPUT:

4
         


        

Answer 1

sizeof expression returns the size required for storage of the type expression evaluates to (see http://en.cppreference.com/w/cpp/language/sizeof). In case of std::string, this contains a pointer to the data (and possibly a buffer for small strings), but not the data itself, so it doesn't (and can't) depend on string length.