Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

iOS Error Handling in Swift 2.0 Error Handling Handling Errors

Just wondering if it's correct to solve the task 1 of 3 in this challenge by writing code this way:

Logic seems to be correct for me and playground shows no errors, however, code isn't accepted by Treehouse. Can you please explain?

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

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

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

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

1 Answer

Hi Anton,

There is some confusion in function parse, it should not take any parametrs and just operate on data dictionary included. so please change it like this and it will be accepted. I tried it:

enum ParserError: ErrorType {
    case EmptyDictionary
    case InvalidKey
}

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

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



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