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iOS Generics in Swift Generic Functions, Parameters and Constraints CSS Background Blend Modes Challenge

Sam Belcher
Sam Belcher
3,719 Points

Generic Functions With Multiple Type Parameters

How can I return "type [U]"?

func map<T, U>(array: [T], transformation: (T) -> U) -> [U] {
  for number in array {
    return [transformation(number)]

1 Answer

Magnus Hållberg
Magnus Hållberg
17,232 Points

Thinking about it, what would you say this for loop you have written is doing? The challenge say you should return an array of type U. What array are you trying to return in this case? Create an array to carry the new values and return it ones the for loop is complete, use the for loop to append the new values.