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iOS Swift Basics (retired) Collections What is a Dictionary?

I am having a trouble with understanding Extra Credit task in Functions with Dictionary


The task goes:

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 so much trouble with tuples. I need help.

4 Answers

First of all, you should think of songDictionary as a parameter, as they are called in Swift. It's the input that you use to get the output.

As for the type, just be happy there's a shorthand. The regular notation involves angle brackets, and can get fairly complicated in certain circumstances.

Here's the code snippet I tried to show you last time:

func getSongInfo(songDictionary: [String: String]) -> (title: String, artist: String, album: String) {
    // You can figure out what goes on in here.

The parameter (insideTheParentheses) is the dictionary. The return value, after the ->, is the tuple.

Okay, this is a function that will extract the three values in a given dictionary, and they want it in a named tuple. What this means is along with specifying the return type for each value (String for each), they want a name that references each value within the tuple. This allows you to later extract a value from that tuple with a recognizable name, rather than just an index.

'''swift func getSongInfo(songDictionary: [String: String]) -> (title: String, artist: String, album: String) { // You can figure out what goes on in here. } '''

After the function declaration, you could save the return value to a variable, then access, for example, the title value like this: songTuple.title PS - have you tried saving each value in the dictionary to a variable before returning the tuple? It makes your code a lot more readable.

Yes I did.

This syntax is new to me: (songDictionary: [String: String])

songDictionary is my variable or better to say named tuple, but why do I have to put type in brackets. Is this only dictionary thing when passing an arguments or...?

I think I get the concept, though I still must memorize the syntax. Thanks for all the help. I think I better understand return values also, I thought that only one word can be after return arrow.