import Foundation
let pattern = #"^([^\t]*)(?:\t([^\t]*))?(?:\t([^\t]*))?(?:\t([^\t]*))?(?:\t([^\t]*))?$"#
let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines)
let testString = #"""
Order 2187405 DvbzVvmLL
Order 4466605 drpTgPmm ItemPrice
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #"$1\t$2\t$3\t$4\t$5\t481"#
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