Why does this string pass through as true in my RegEx statement match in my Swift code?

Question

Why does the following sentence:

let potential = "Kaline bypassed the Minors to join the Tigers at 18. By 20"

pass through this RegEx if statement:

if (potential.matches("(?i)No.\\s?-?\\s?[A-Z0-9]") ||
potential.matches("(?i)N0.\\s?-?\\s?[A-Z0-9]")) 
{
   print("in"
}

extension String {
    func matches(_ regex: String) -> Bool {
        return self.range(of: regex, options: .regularExpression, range: nil, locale: nil) != nil
    }
}

"nors" matches your first regex. https://regex101.com/r/h7BhWb/1 What is your goal? — Leo Dabus, Nov 29 '20 at 04:42
Ohhhh I see. Because of my optional spaces and - it's going right into the A-Z0-9. I'll fix it. thank you! — Ethan Allen, Nov 29 '20 at 04:59
if `"No.-1"` Should be a successful match. I think the issue is that you forgot to escape the period. — Leo Dabus, Nov 29 '20 at 04:59
You can also use a single pattern instead of 2 using a character class `[0o]` to match each of the listed characters `(?i)N[0o]\\.\\s?-?\\s?[A-Z0-9]` https://regex101.com/r/8eSFAm/1 — The fourth bird, Nov 29 '20 at 11:30

score 1 · Accepted Answer · answered Nov 29 '20 at 12:21

Instead of checking using 2 patterns, you can use a character class [0o] and use a single pattern.

As already mentioned in the comments, you have to escape the dot to match it literally or else it will match any character.

(?i)N[0o]\\.\\s?-?\\s?[A-Z0-9]

Regex demo

Why does this string pass through as true in my RegEx statement match in my Swift code?

1 Answers1