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 
}