How to Use map, filter, reduce

Steps

1. Paste the code into a Swift file or playground.
2. Run it once to verify the output.
3. Adjust the inputs to match your use case.

Copy and paste

import Foundation

let numbers = [1, 2, 3, 4, 5]
let evens = numbers.filter { $0 % 2 == 0 }
let squares = numbers.map { $0 * $0 }
let total = numbers.reduce(0, +)

print(evens)
print(squares)
print(total)

Notes

• Keep functions small and focused for reuse.
• Prefer safe APIs like optionals and guards.