import Foundation
let pattern = ##"(#table\d+)|\((\w{1,2})(\))"##
let regex = try! NSRegularExpression(pattern: pattern)
let testString = ##"<p id="para"> demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test demo<a href="#table1(t1)" id="ytD2F">table1</a> test demo test demo test demo test demo test demo <a href="#table2(t2)" id="ytD2F">table2</a> demo test demo test demo test demo test demo test demo test demo test demo test demo test demo test </p>"##
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