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iOS Error Handling in Swift Error Handling Handling Errors

Posted by Fredrick Barrett
Fredrick Barrett
2,068 Points

my do catch block is giving me errors, what am I doing wrong?

Im looking over my notes on how to create a do catch block and I can't see what im doing wrong

error.swift 
enum ParserError: Error {
  case emptyDictionary
  case invalidKey
}

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

  func parse() throws {
    guard let incomingData = data else { throw ParserError.emptyDictionary }

    guard incomingData.keys.contains("someKey") else { throw ParserError.invalidKey }
  }

  do { try parse()
}

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

do {
  let attempt = try parse()
  } 
 catch ParserError {
    print(invalidKey)
    }

1 Answer

Johnny Nguyen
Johnny Nguyen
3,875 Points
Johnny Nguyen
Johnny Nguyen
3,875 Points

You did really good at task 1. These below are task 2 and 3. Look at the code and the task to improve your understanding. Good Luck!

Challenge task 2 of 3

do {
try parser.parse()
} catch let error {
    print("\(error)")
}

Challenge task 3 of 3

do {
try parser.parse()
} catch ParserError.emptyDictionary {
    print("emptyDictionary")
} catch ParserError.invalidKey {
    print("invalidKey")
}