import Foundation
let pattern = ##"((\b\d+)(?:\sPI?N ?#? ?))|((?:PI?N ?#? ?)(\d+))"##
let regex = try! NSRegularExpression(pattern: pattern, options: [.anchorsMatchLines, .caseInsensitive])
let testString = ##"""
9999XX00999X PIN # 999999
9999XX000999 - PIN#909999
XXXXX XX PIN #9099999
9999XX99X PIN999099
99XX999X PN 9999999
9999999 PIN
90PA999 PN 999999
999009 PIN#
99PA99 PN#9999999
PIN 999990
XXXPIN990999
PIN#999099
PIN# 9990909
PIN#9099999*
"""##
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #"test\1"#
let result = regex.stringByReplacingMatches(in: testString, range: stringRange, withTemplate: substitutionString)
print(result)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Swift 5.2, please visit: https://developer.apple.com/documentation/foundation/nsregularexpression