Advanced Pattern Matching

Tuple Pattern

released Fri, 15 Feb 2019
Swift Version 5.0

Tuple Pattern

We have a full article on tuples, but here is a quick overview:

let age = 23
let job: String? = "Operator"
let payload: Any = NSDictionary()

switch (age, job, payload) {
case (let age, _?, _ as NSDictionary):
default: ()

Here, we're combining three values into a tuple (imagine they're coming from different API calls) and matching them in one go. Note that the pattern achieves three things:

  1. It extracts the age
  2. It makes sure there is a job, even though we don't need it
  3. It makes sure that the payload is of kind NSDictionary even though we don't need the actual value either.