Reading Notes for Objective C #

I suddenly saw a reading note about Mr. Bill Wagner's Objective C #. I thought it was a good one and I am going to link it here. If anyone has the Chinese version of this book, please send me a thank you first.

Objective C # Reading Notes (1) Item 1: Always use properties instead of accessible data members
Item 1: Always use attributes instead of directly accessing data members
Objective C # Reading Notes (2) Item 2: prefer readonly to const Item 2nd:When defining constants, use them first.ReadonlyInsteadConst
Objective C # Reading Notes (3) Item 3: preferIsOrAsOperators to casts Item 1: type conversion using is/AS is preferred Objective C # Reading Notes (4) Item 4: Use conditional attributes instead # If
Item 1: use an attribute with conditions instead # If