Swift Style

Indexing and Enumerating Collections

Swift offers helpful ways to optimize the way you interact with collections. Here are some tips and pointers about collections that you may want to adopt into your preferred practices.

Iterating Across Slices

Avoid indices when you can iterate across a slice. This transfers complexity from the body to the loop declaration, creating cleaner implementations:

for value in array[2...5] { f(value) } // yes

for index in 2...5 { f(array[index]) } // no

Retaining Slices

Slices are great for iterating and creating subcollections, but a tiny ArraySlice can be backed by a much larger array. Don’t hold onto slices any longer than you need to. When you require access for significant periods of time, convert ...