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3 min readFeb 17, 2026
Swift

How to Use typealias

Improve readability by renaming complex types.

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

typealias Completion = (Result<String, Error>) -> Void

func loadData(completion: Completion) {
    completion(.success("OK"))
}

Notes

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