Dart Requires Chilkat v11.1.0+

Regular Expression Replace Full Matches

See more Regular Expressions Examples

Demonstrates replacing the full matches of a regular expression.

Note: Chilkat uses PCRE2. See PCRE2 Regular Expressions
Also see: PCRE2 Performance

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  final subject = 'John Anders, +_+_+ Mary Robins \$\$\$\$';
  final pattern = '\\w+\\s+\\w+';

  final sb = CkStringBuilder();
  sb.append(subject);

  final json = CkJsonObject();
  json.emitCompact = false;

  final timeoutMs = 2000;
  var numMatches = sb.regexMatch(pattern, json, timeoutMs);
  if (numMatches < 0) {
    // Probably an error in the regular expression.
    // Suggestion: Use AI to help create and/or diagnose regular expressions.
    print(sb.lastErrorText);
    return;
  }

  // Examine the matches:
  print(json.emit());

  // {
  //   "match": [
  //     {
  //       "group": [
  //         {
  //           "cap": "John Anders",
  //           "idx": 0,
  //           "len": 11
  //         }
  //       ]
  //     },
  //     {
  //       "group": [
  //         {
  //           "cap": "Mary Robins",
  //           "idx": 19,
  //           "len": 11
  //         }
  //       ]
  //     }
  //   ]
  // }

  final sbTemp = CkStringBuilder();

  var i = 0;
  numMatches = json.sizeOfArray('match');
  while (i < numMatches) {

    json.i = i;

    // The full match is always in group 0.
    sbTemp.clear();
    json.stringOfSb('match[i].group[0].cap', sbTemp);

    // Indicate that we wish to replace the full match with it's value converted to uppercase.
    sbTemp.toUppercase();
    json.updateSb('match[i].group[0].rep', sbTemp);

    i++;
  }

  // The JSON now has replacement strings:
  print(json.emit());

  // {
  //   "match": [
  //     {
  //       "group": [
  //         {
  //           "cap": "John Anders",
  //           "idx": 0,
  //           "len": 11,
  //           "rep": "JOHN ANDERS"
  //         }
  //       ]
  //     },
  //     {
  //       "group": [
  //         {
  //           "cap": "Mary Robins",
  //           "idx": 19,
  //           "len": 11,
  //           "rep": "MARY ROBINS"
  //         }
  //       ]
  //     }
  //   ]
  // }

  // Call RegexReplace to update the StringBuilder with the replacements.
  try {
    sb.regexReplace(json);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Result after doing replacements:');
  print(sb.getAsString());

  // Result after doing replacements:
  // JOHN ANDERS, +_+_+ MARY ROBINS $$$$
}