Displaying multiple values in for statement in Swift - swift

Question

Hi I am new to programming. I apologize beforehand if this is a stupid question, but I'm learning about For loops. The below is an example code I understand. I know how to write a basic For loop that iterates through a single variable in each loop, but how do I use a For loop to display multiple values in one loop. Example:
let treeArray = ["Pine", "Oak", "Yew", "Maple", "Birch", "Myrtle"]
for tree in treeArray {
print(tree)
}
I want to be able to print three variables in one loop so the code would print
Pine Oak Yew on one line
Maple Birch Myrtle and on the next
Instead of
Pine
Oak
Yew
Maple
Birch
Myrtle
Thanks!

Answer 1

You could use .enumerated() to pair the index with the element and then print(_:terminator:) using index % 3 to select the appropriate terminator (newline "\n" or space " "):
let treeArray = ["Pine", "Oak", "Yew", "Maple", "Birch", "Myrtle"]
for (index, tree) in treeArray.enumerated() {
print(tree, terminator: index % 3 == 2 ? "\n" : " ")
}
Output:
Pine Oak Yew
Maple Birch Myrtle
The general case: printing n items per line
In general, for printing n items per line:
print(tree, terminator: index % n == n - 1 ? "\n" : " ")
or equivalently:
print(tree, terminator: (index + 1) % n == 0 ? "\n" : " ")
If you want the last item to always be followed by a newline, then add an addition check for that:
print(tree, terminator: index % n == n - 1 || index == treeArray.endIndex - 1 ? "\n" : " ")

Answer 2

Use an array to store trees and
joined(separator: String)
on array to stitch them together.
let treeArray = ["Pine", "Oak", "Yew", "Maple", "Birch", "Myrtle"]
var treeNames = [String]()
for (count, tree) in treeArray.enumerated() {
treeNames.append(tree)
if ((count + 1) % 3) == 0 {
let treeLine = treeNames.joined(separator: " ")
print(treeLine)
treeNames.removeAll()
}
}