For loops

Swift has a few ways of writing loops, but their underlying mechanism is the same: run some code repeatedly until a condition evaluates as false.

The most common loop in Swift is a for loop: it will loop over arrays and ranges, and each time the loop goes around it will pull out one item and assign to a constant.

For example, here’s a range of numbers:

let count = 1...10

We can use a for loop to print each item like this:

for number in count {
    print("Number is \(number)")
}

We can do the same with arrays:

let albums = ["Red", "1989", "Reputation"]

for album in albums {
    print("\(album) is on Apple Music")
}

If you don’t use the constant that for loops give you, you should use an underscore instead so that Swift doesn’t create needless values:

print("Players gonna ")

for _ in 1...5 {
    print("play")
}

SPONSORED In-app subscriptions are a pain to implement, hard to test, and full of edge cases. RevenueCat makes it straightforward and reliable so you can get back to building your app. Oh, and it's free if your app makes less than $10k/mo.

Learn more

Sponsor Hacking with Swift and reach the world's largest Swift community!