Tune your header file Part 2: Nullability

In the first post I put the focus on the initializers, in this post I would like to put the nullability into the spotlight. I would also explain why is it a good practice, and how it will help you migrate your existing Objective-C code into Swift. Nullable/Nonnull The idea behind using the nullable/nonnull keyword ...

Key-Value Coding aggregation operations on collections

If you have ever worked with SQL queries and the aggregate functions (or in worst case with spreadsheet applications like Excel or Numbers), this topic will be familiar to you. It is usually overlooked, but the Key-Value Coding can also benefit from those functions on collections, like NSArray or NSSet. Obviously the type should support ...