Zip for combining sequences in Swift

Introduction

Zip helps you join two lists together, pairing items from each list side by side. It makes working with related data easy.

You have two lists like names and ages and want to pair each name with its age.

You want to loop over two sequences at the same time.

You need to combine two arrays into one list of pairs for easy processing.

Syntax

Swift

let zippedSequence = zip(sequence1, sequence2)

The result is a sequence of pairs (tuples).

If sequences have different lengths, zip stops at the shortest one.

Examples

This pairs numbers with letters: (1, "a"), (2, "b"), (3, "c")

Swift

let numbers = [1, 2, 3]
let letters = ["a", "b", "c"]
let zipped = zip(numbers, letters)
for pair in zipped {
    print(pair)
}

Zip stops at shortest list, so only pairs Anna and Bob with first two scores.

Swift

let names = ["Anna", "Bob"]
let scores = [95, 82, 77]
let zipped = zip(names, scores)
for (name, score) in zipped {
    print("\(name): \(score)")
}

Sample Program

This program pairs each fruit with its color and prints the pairs.

Swift

let fruits = ["Apple", "Banana", "Cherry"]
let colors = ["Red", "Yellow", "Dark Red"]

let zippedFruits = zip(fruits, colors)

for (fruit, color) in zippedFruits {
    print("\(fruit) is \(color)")
}

Important Notes

Zip creates pairs as tuples, which you can unpack in loops.

If you want to combine more than two sequences, you can zip multiple times or use other methods.

Summary

Zip combines two sequences into pairs.

It stops when the shortest sequence ends.

Use it to work with related data side by side.