CODEWITHSUNDEEP
swiftswift2
Aidan Gomez
Aidan Gomez

Reputation: 8627

Swift: How does zip() handle two different sized collections?

The zip() function takes two sequences and returns a sequence of tuples following:

output[i] = (sequence1[i], sequence2[i])

However, the sequences can potentially be of different dimensions. My question is how does the Swift language deal with this?

The docs were utterly useless.

Seems to me, there are two possibilities (in Swift):

Upvotes: 11

Views: 3160

Answers (2)

pkamb
pkamb

Reputation: 34993

Apple's zip(_:_:) documentation has since been updated to answer this question:

https://developer.apple.com/documentation/swift/1541125-zip

If the two sequences passed to zip(_:_:) are different lengths, the resulting sequence is the same length as the shorter sequence. In this example, the resulting array is the same length as words:

let words = ["one", "two", "three", "four"]
let naturalNumbers = 1...Int.max
let zipped = Array(zip(words, naturalNumbers))
// zipped == [("one", 1), ("two", 2), ("three", 3), ("four", 4)]

Upvotes: 0

Aidan Gomez
Aidan Gomez

Reputation: 8627

Swift uses the first option, the resulting sequence will have a length equal to the shorter of the two inputs.

For example:

let a: [Int] = [1, 2, 3]
let b: [Int] = [4, 5, 6, 7]

let c: [(Int, Int)] = zip(a, b) // [(1, 4), (2, 5), (3, 6)]

Upvotes: 15

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