Welcome to the Treehouse Community
Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.
Looking to learn something new?
Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.
Start your free trialMichael Castro
11,959 PointsChallenge Task 1 of 1 In the editor, we're using the map function on an array of numbers to perform an operation.
What's wrong with what I've done here? I'm using a trailing closure and short hand syntax to double each value
func doubleValue(i: Int) -> Int {
return i * 2
}
let doubler = doubleValue
let doubledValues = [1,2,3,4].map() { $0 * 2 }
3 Answers
Brandon Maldonado Alonso
10,050 PointsI'm not sure if it is still useful for you, but you just have to delete the parenthesis from map like this: let doubledValues = [1,2,3,4].map { $0 * 2 }
carriebarnett
16,732 PointsThis also worked for me:
let doubledValues = [1,2,3,4] //.map(doubler)
let doubler = doubledValues.map { $0 * 2 }
func double(_ i: Int) -> Int {
return i * 2
}
print(doubler)
Mina Makar
5,421 Pointsfunc double(_ i: Int) -> Int { return i * 2 }
let array = [1,2,3,4]
let doubler = array.map { $0 * 2}