将两个数组的元素相加

Question

I have 2 Array of type Int like this

let arrayFirst = [1,2,7,9]
let arraySecond = [4,5,17,20]

I want to add the elements of each array, like arrayFirst[0] + arraySecond[0], arrayFirst[1] + arraySecond[1] an so on and assign it to another array, so the result of the array would be like

[5, 7, 24, 29]

What would be the best practice to achieve this using swift3

Answer 1

You can add both the arrays like this

let arrayFirst = [1,2,7,9]
let arraySecond = [4,5,17,20]

let result = zip(arrayFirst, arraySecond).map(+)
print(result)

Answer 2

let arrayFirst = [1,2,7,9]
let arraySecond = [4,5,17,20]

First zip(_:_:) them, to produce a sequence that acts like array of pairs

let zipped = zip(arrayFirst, arraySecond)
// zipped acts like [(1, 4), (2, 5), (7, 17), (9, 20)]

Then map(_:) over the tuples, and apply the + operator:

let result = zipped.map(+)
// result is [5, 7, 24, 29]

All together:

let result = zip(arrayFirst, arraySecond).map(+)