I have a string array called prodIDArr having values like so...
["1","2","3","4","5","6","7","8","9","10"]
But when I do something like so..
let maxVal = prodIDArr.max()
I get the value of maxVal as 9 and not 10.
What could be the reason for this...?
That is an array of strings, and those are compared lexicographically:
"1" < "10" < "2" < ... < "9"
For example "10" < "2" because the initial characters already
satisfy "1" < "2". (For the gory details, see for example
What does it mean that string and character comparisons in Swift are not locale-sensitive?.)
Using an array of integers would be the best solution:
let prodIDArr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
let maxId = prodIDArr.max()
print(maxId) // Optional(10)
If that is not possible then you can enforce a numeric comparison with
let prodIDArr = ["1","2","3","4","5","6","7","8","9","10"]
let maxId = prodIDArr.max(by: { $0.compare($1, options: .numeric) == .orderedAscending })
print(maxId) // Optional("10")
You can also map your original String Array to an Int Array
let prodIDArr = ["1","2","3","4","5","6","7","8","9","10"]
let prodNumArray = prodIDArr.map { input in Int(input)!} // or { Int($0)! }
print(prodNumArray.max()!)
