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iOS Error Handling in Swift 2.0 Error Handling Handling Errors

Manuel Pascual
Manuel Pascual
4,676 Points
Posted by Manuel Pascual
Manuel Pascual
4,676 Points

I really don't know how to pass this challenge... Need help!

I really don't know how to pass this challenge... Need help!

error.swift 
enum ParserError: ErrorType {
  case EmptyDictionary
  case InvalidKey
}

struct Parser {
  var data: [String : String?]?

  func parse(dict: [String : String?]?) throws {
        guard let diccionario = dict else {
            throw ParserError.EmptyDictionary
        }
        guard let emptyKey = dict?["someKey"] else {
            throw ParserError.InvalidKey
        }
    }
}

let data: [String : String?]? = ["someKey": nil]
let parser = Parser(data: data)

2 Answers

Victor Santos
Victor Santos
3,585 Points
Victor Santos
Victor Santos
3,585 Points

The Struct “Parse” it's expecting a "data" and this data you should to pass to the function “parse", so you do not need to add additional parameters, and them you should to validate whether guard (data != nil) else{ throw} and guard let someVar = data["someKey"] else{ throw } remember the exclamation mark data!["someKey"]

enum ParserError: ErrorType {
  case EmptyDictionary
  case InvalidKey
}

struct Parser {
  var data: [String : String?]?

  func parse() throws {
    guard (data != nil)  else {
      throw ParserError.EmptyDictionary
    }
    guard let someKey = data!["someKey"] else {
      throw ParserError.InvalidKey
    } 
  }
}

let data: [String : String?]? = ["someKey": nil]
let parser = Parser(data: data)
jcorum
jcorum
71,830 Points
jcorum
jcorum
71,830 Points

Try this for the struct for the 1st part:

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
        }

    }
}

Note that the parse() function has no parameters, and that this version uses the stored property data. Otherwise you were pretty much there.