Swift: Ambiguous reference to member 'map'

Question

I\'m reading \"The swift programming language 4.2\". In the beginning chapter, page 23, I have this following requirement:

Rewrite the closure to return z

Answer 1

Rather than annotating the parameter type you have to specify the return type of the closure

let myArray = [1, 2, 3, 4, 5] // You don't even need to annotate the array, the compiler knows the type.

let result = myArray.map({ number -> Int in
    if number % 2 != 0 {
        return 0
    } else {
        return number
    }
})

Or with trailing closure syntax and shorthand argument names. In this case the compiler can infer everything

let result = myArray.map { $0 % 2 != 0 ? 0 : $0 }