How to throw errors using strings
Swift version: 5.2
Throwing functions in Swift are the main way we have of signaling that an operation failed, but sometimes it can be annoying to define a whole new error enum just to report a simple failure.
With a small extension to String you can make the whole process easier:
extension String: LocalizedError {
public var errorDescription: String? { return self }
}With that change you can now throw strings as errors, and they work just like regular errors. For example, you can create a throwing function like this one:
func doDangerousThing() throws {
throw "I'm sorry, Dave, I can't do that."
}Then attempt to run it and print any errors that are thrown, like this:
do {
try doDangerousThing()
} catch {
print(error.localizedDescription)
}This only really works for errors that have one case, because you can’t match specific string errors.
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Available from iOS 8.0
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