SOLVED: Double the value of numbers in array

@nemtna

May '20

So, i'm doing the practice in the app and there's one question that i just cannot get past:

"Write code that doubles all the numbers in this array: let numbers = [1, 3, 5, 7, 9] <

The hint is to use a for loop, and I've tried a variety of this code:

for number in numbers {
 number * 2
}

for number in numbers {
 let doubled = number * 2
}

No success. What exactly is the app lookimg for? I'd tried replacing the indexes, creating a new array... nada.

@Volker88

May '20

You can create an empty array in where you append the doubled values of your numbers array.

var doubledWithLoop = [Int]()
for number in numbers {
    doubledWithLoop.append(number * 2)
}
print(doubledWithLoop)

But the easier and better way is using .map()

let numbers = [1, 3, 5, 7, 9]
let doubledWithMap = numbers.map { $0 * 2 }
print(doubledWithMap)

Output of this both approaches will be

[2, 6, 10, 14, 18]

@nemtna

May '20

Creating an empty array and appending the doubled number worked! Thanks!

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