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

Posted by aaron du
aaron du
5,946 Points

generic functions with multiple type parameters

i need help with this code challenge. i have been doing all i could and tried my best to pass this challenge, but my code just couldn't be compiled. help please!!!! thanks

generics.swift 
func times4(aray: [Int]) -> [Int] {

let size = aray.count - 1
for size in aray {

aray(0...size) * aray(0...size)


}

}






func map<T,U>(array: [T], transformation: (T) -> U) -> [U] {
transformation = times4(array)
return transformation
}

1 Answer

Nathan F.
Nathan F.
30,773 Points
Nathan F.
Nathan F.
30,773 Points

To get started, the code challenge only wants you to create a map<T,U> function with a transformation parameter. Treehouse will test the map function by supplying different arguments to transformation, so you don't need to add a times4 function or call it in your map function.

aaron du
aaron du
5,946 Points

thanks, got it

Gavin Hobbs
Gavin Hobbs
5,205 Points
Gavin Hobbs
Gavin Hobbs
5,205 Points

aaron du what was your final answer? I can't figure it out. This is my code...

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