Simple Regex Checker in Swift

regex.playground

class RegexManager {
  
  var regex: NSRegularExpression
  
  init?(regexPattern: String) {
    do {
      regex = try NSRegularExpression(pattern: regexPattern)
    } catch {
      // Invalid pattern
      return nil
    }
  }
  
  func checkIfTextMatchesRegex(textToCheck: String) -> Bool {
    let textToCheckRange = NSRange(location: 0, length: textToCheck.utf16.count)
    
    return regex.firstMatch(in: textToCheck,
                            options: [],
                            range: textToCheckRange) != nil
  }
}

// Regex pattern
let regexPattern = "[a-z]at"

// Regex test Strings
let testString = "hat"
let testString2 = "pants"

let regexManager = RegexManager(regexPattern: regexPattern)

regexManager?.checkIfTextMatchesRegex(textToCheck: testString)
regexManager?.checkIfTextMatchesRegex(textToCheck: testString2)

Inspired after reading this great article https://www.hackingwithswift.com/articles/108/how-to-use-regular-expressions-in-swift