Search Array of Dictionaries for Value in Swift

Question

I\'m new to Swift and taking a class to learn iOS programming. I find myself stumped on how to search in an array of dictionaries for a string value and dump the string valu

Answer 1

Airspeed Velocity's answer is very comprehensive and provides a solution that works. A more compact way of achieving the same result is using the filter and map methods of swift arrays:

func favoriteDrinksArrayForCharacters(characters:Array>) -> Array {
    // create an array of Strings to dump in favorite drink strings
    return characters.filter { $0["favorite drink"] != nil }.map { $0["favorite drink"]! }
}

The filter takes a closure returning a boolean, which states whether an element must be included or not - in our case, it checks for the existence of an element for key "favorite drink". This method returns the array of dictionaries satisfying that condition.

The second step uses the map method to transform each dictionary into the value corresponding to the "favorite drink" key - taking into account that a dictionary lookup always returns an optional (to account for missing key), and that the filter has already excluded all dictionaries not having a value for that key, it's safe to apply the forced unwrapping operator ! to return a non optional string.

The combined result is an array of strings - copied from my playground:

["prune juice", "tea, Earl Grey, hot"]