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Jeff Ripke
41,989 PointsPerfect! We're almost done. Rather than a generic catch clause, let's pattern match on the specific errors so that we ca
Unable to figure this out, what am I doing wrong?
enum ParserError: ErrorType {
case EmptyDictionary
case InvalidKey
}
struct Parser {
var data: [String : String?]?
func parse() throws {
guard let parsedData = data else {
throw ParserError.EmptyDictionary
}
guard parsedData.keys.contains("someKey") else {
throw ParserError.InvalidKey
}
}
}
let data: [String : String?]? = ["someKey": nil]
do {
let data: [String : String?]? = ["someKey": nil]
let parser = try Parser(data: data)
try parser.parse()
try parser.data
} catch ParserError.EmptyDictionary {
print("no data")
} catch ParserError.InvalidKey {
pring("invalide key")
}
1 Answer
Michael Reining
10,101 PointsHi Jeff,
You are super close. Just update your syntax for the error handling like this. You do have a typo, however, that might cause the problem.
pring("invalide key") // change pring to print ;)
My final code looked like this. I did not even print anything.
enum ParserError: ErrorType {
case EmptyDictionary
case InvalidKey
}
struct Parser {
var data: [String : String?]?
func parse() throws {
guard let data = data else {
throw ParserError.EmptyDictionary
}
guard let key = data["somekey"] else {
throw ParserError.InvalidKey
}
}
}
let data: [String : String?]? = ["someKey": nil]
do {
let parser = try Parser(data: data)
try parser.parse()
} catch ParserError.EmptyDictionary {
// deal with empty dictionary
}
catch
ParserError.InvalidKey {
// deal with invalid key
}
I hope that helps,
Mike
PS: Thanks to the awesome resources on Team Treehouse, I launched my first app.
Now you can practice writing Swift code directly on your iPhone :-)