1.4 Tuples

• ordered list of values
• no limit to the # of items
• can be of any type, not necessarily the same (can be inferred)
• useful for temporary groups of related values
• not useful for the creation of complex data structures

Assigning

// declaration - create but don't initialize<br>
var rectangle0: (Int, Int)

// create and initialize with initial values
let rectangle1 = (200, 100)

// create and initialize with initial values and names (preferred)
var rectangle2 = (width:200, height:100)

Decomposing

// decompose with .dot syntax -> 100<br>
rectangle1.1
// decompose with name -> 200
rectangle2.width

// -> a = 200, b = 100
let (a, b) = rectangle1
let (_, e) = rectangle2

_ → shows that you are ignoring this part for now

Decomposing from a Function

• let a variable = tuple, then reference by var names directly

// function returning a tuple
func getSongAndLength() 
   -> (name: String, length: Int?) {
      return ("Centerfold", nil)
}

// assignment of a tuple from a function
let (name, length) = getSongAndLength()
print("The song is \(name) and it's \(length ?? 90) seconds long")

• length is an Optional (Int?) and can be set to nil
• assign names up front to identify tuple values and use them
• ?? → Nil-Coalescing Operator – used to assign a default value for an Optional