if you ever asked to do some weird password validation (min 6, max 8 digits, no more than 3 repeating or sequential numbers)

String.swift

func isValidPassword() -> Bool {
	let regex = "\\b(?!.*?(?:0(?:12)|123|234|3(?:45|21)|4(?:56)|5(?:67)|6(?:78)|7(?:89)))(?!.*?(.)\\1{2})[0-9]{6,8}\\b"
	let sequentialOrRepeated = NSPredicate(format: "SELF MATCHES %@", regex)
	return sequentialOrRepeated.evaluate(with: self)
}

change the {6,8} for range and {2} for repeating or sequential parts