Merge sub-array in Swift-CodePudding

I have an array and I want to merge it.

This is the array:

let numbers = [ [ 1, 2, 3 ], [ 4, 5, 6 ] ]

I need a output like this:

let result = [ [ 1, 4 ], [ 2, 5 ], [ 3, 6 ] ]

CodePudding user response：

let numbers = [[1,2,3], [4,5,6]]

let result = zip(numbers[0], numbers[1]).map { [$0.0, $0.1]}

print(result) // -> [[1, 4], [2, 5], [3, 6]]

If the array has more elements the following would work.

let numbers = [[1,2,3], [4,5,6], [7,8,9]]

var result : [[Int]] = []

for n in 0...numbers.first!.count-1{
    result.append(numbers.compactMap { $0[n] })
}

print(result) // -> [[1, 4, 7], [2, 5, 8], [3, 6, 9]]

CodePudding user response：

You can use the zip global function, which, given 2 sequences, returns a sequence of tuples and then obtain an array of tuples by using the proper init.

var xAxis = [1, 2, 3, 4]
var yAxis = [2, 3, 4, 5]
let pointsSequence = zip(xAxis, yAxis)
let chartPoints = Array(pointsSequence)
print(chartPoints)

And then you can access the tuples like this :

let point = chartPoints[0]
point.0 // This is the 1st element of the tuple
point.1 // This is the 2nd element of the tuple