OC sorting 3

// # Import "women. H"

@ Class women; // use the following women as a string instead of a class.

// Unknown type name "women"

// Unrecognized women type

// Cause: # When the import header file is used, the content in the header file will be copied. When the women class is used, it is still undefined to Ray, so it cannot be identified. Typical loop import problems

// Solution: This class cannot be used as a class. in the H file, @ class women; is used to declare women as a string. in use. but it does not have the content in the class, so you need. # import "women. h"