"Effective objective-c" Reading notes (2)

Minimize the introduction of additional header files in the header file of the class

Use "forward declaration" to introduce header files when there is a need, reducing the number of header files that the class's users need to introduce, and reducing compilation time.

The forward declaration also solves the problem of two classes referencing each other. Using #import instead of # include directives does not cause a dead loop, but one of the two classes cannot be compiled correctly.

Each time you refer to a different header file in the header file, ask yourself if it is necessary to do so, and if you can replace the reference with a forward declaration, use a forward declaration instead of the introduction.

"Effective objective-c" Reading notes (2)