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Billy Potts
Courses Plus Student 2,344 Pointshow do i pattern match this Catch
Perfect! We're almost done. Rather than a generic catch clause, let's pattern match on the specific errors so that we can log better error messages. In this task, change the catch statement to include specific error cases. Like before you can just log an error message of your choosing.
enum ParserError: ErrorType {
case EmptyDictionary
case InvalidKey
}
struct Parser {
var data: [String : String?]?
func parse() throws {
guard let _ = data else {
throw ParserError.EmptyDictionary
}
guard let _ = data!["someKey"] else {
throw ParserError.InvalidKey
}
}
}
let data: [String : String?]? = ["someKey": nil]
do {
let parser = try Parser(data: data).parse()
} catch ParserError.EmptyDictionary {
print("Error")
}
2 Answers
jcorum
71,830 PointsWell, I tried testing this about a dozen times in the editor but I kept getting Oh no!s each time. So here it is.
It should get you finished, as you are almost there:
do {
let parser = Parser(data: data)
try parser.parse()
} catch { ParserError.EmptyDictionary }
catch {
ParserError.InvalidKey
}
Joshua Hardy
17,317 Pointsdo {
let parser = Parser(data: data)
try parser.parse()
} catch { ParserError.emptyDictionary }
catch {
ParserError.invalidKey
}
Joshua Hardy
17,317 Pointslower case letters instead of upper case for the .emptyDictionary & .invalidKey
Li Lin
Courses Plus Student 2,654 PointsLi Lin
Courses Plus Student 2,654 PointsWhy is it correct? I didn't see any pattern match in it.