gistfile1.swift

//“Rewrite the closure to return zero for all odd numbers.”
//Excerpt From: Apple Inc. “The Swift Programming Language.” iBooks. https://itun.es/pl/jEUH0.l


var numbers : UInt[] = [20, 19, 10, 13, 432, 432432, 80];


// Could this be more efficient: 
let mapped : Array<UInt> =  numbers.map({
    (number : UInt) -> UInt in
    let multiplier : UInt = ~(number % 2 + (UInt.max-1));
    return number * multiplier;
});


// Than (using ifs) this:  ? 


let mapped2 : Array<UInt> =  numbers.map({
    (number : UInt) -> UInt in
    
    if (number % 2) == 1 {
        return 0;
    } else {
        return number;
    }
});