How to Create Custom Errors

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

enum LoginError: Error {
    case invalidCredentials
    case lockedOut
}

func login(user: String, password: String) throws {
    throw LoginError.invalidCredentials
}

Notes

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