import Foundation
let pattern = #"^\s*(\+[0-9][0-9]\s*|0|)(7.*)"#
let regex = try! NSRegularExpression(pattern: pattern, options: [.anchorsMatchLines, .caseInsensitive, .allowCommentsAndWhitespace])
let testString = #"""
+41 79 123 456 78
+417612345678
076 123 456 78
07812345678
7712345678
+41 47 123 456 78
+413212345678
021 123 456 78
02212345678
3412345678
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #"$2"#
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