Swift Functional Programming - Second Edition

for loops

Swift provides for and for-in loops. We can use the for-in loop to iterate over items in a collection, a sequence of numbers such as ranges, or characters in a string expression. The following example presents a for-in loop to iterate through all items in an Int array:

let scores = [65, 75, 92, 87, 68] var teamScore = 0 for score in scores {     if score > 70 {         teamScore = teamScore + 3     } else {         teamScore = teamScore + 1     } } 

and over dictionaries:

for (cheese, wine) in cheeseWinePairs{     print("\(cheese): \(wine)") } 

As C styles for loops with incrementers/decrementers are removed from Swift 3.0, it is recommended to use for-in loops with ranges instead, as follows:

var count = 0 for i in 0...3 {     count + = i }