Help With Extra Credit Project Passing Dictionary to Function

can you post what the extra credit assignment is? does your code work? is there an error?

The assignment is: Write a function that accepts a Dictionary as parameter and returns a named tuple. The dictionary should contain the following keys: title, artist and album.

I have tried this too:

// Playground - ExtraCredit4

import UIKit

var Song1 = ["Title" : "Freebird", "Artist" : "Lynyrd Skynyrd", "Album" : "Thyrty"] var Song2 = ["Title" : "Money", "Artist" : "Pink Floye", "Album" : "Dark Side Of The Moon"] var Song3 = ["Title" : "Another Brick In The Wall", "Artist" : "Pink Floyd", "Album" : "Another Brick In The Wall"]

func myMusic(song: Dictionary) -> (title: String, artist: String, album: String) { return ("Title: (title)\n","Artist: (artist)\n", "Album: (album)\n")

} println(myMusic(Song1))

I get an error that reference to generic type dictionary requires an argument

alright the problem is in your dictionary type for your parameter. the swift eBook states:

You can also write the type of a dictionary in shorthand form as [Key: Value]

so knowing that functions have parameters in the form of

func someFunc(parameterName: Type) {}

you can create your function that takes a dictionary as a parameter and returns a named tuple like so

func myMusic(myDict: [String: String]) -> (title: String, artist: String, album: String) {

}

then using the myDict parameter we can access the values for the keys of the dict and return them in a tuple. the eBook states:

You can also use subscript syntax to retrieve a value from the dictionary for a particular key. Because it is possible to request a key for which no value exists, a dictionary’s subscript returns an optional value of the dictionary’s value type. If the dictionary contains a value for the requested key, the subscript returns an optional value containing the existing value for that key. Otherwise, the subscript returns nil:

so you can force unwrap the values for the keys or use optional binding which would be safer. I used forced unwrapping below for simplicity

func myMusic(myDict: [String: String]) -> (title: String, artist: String, album: String) {

     return (myDict["title"]!, myDict["artist"]!, myDict["album"]!)
}

We're getting closer:

// Playground - ExtraCredit4

import UIKit

var Song1 = ["Title" : "Freebird", "Artist" : "Lynyrd Skynyrd", "Album" : "Thyrty"] var Song2 = ["Title" : "Money", "Artist" : "Pink Floye", "Album" : "Dark Side Of The Moon"] var Song3 = ["Title" : "Another Brick In The Wall", "Artist" : "Pink Floyd", "Album" : "Another Brick In The Wall"]

func myMusic(songs: [String: String]) -> (title: String, artist: String, album: String) { return (songs["title"]!,songs["artist"]!,songs["album"]!)

} println(myMusic(Song1))

error on return line:

Execution was interrupted, reason: EXC_BAD_INSTRUCTION (code=EXC_1386_INVOP,subcode=0x0).