.NET Core C#

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

.NET Core C#

bool success = false;

success = false;

string subject = "John Anders, +_+_+ Mary Robins $$$$";
string pattern = "\\w+\\s+\\w+";

Chilkat.StringBuilder sb = new Chilkat.StringBuilder();
sb.Append(subject);

Chilkat.JsonObject json = new Chilkat.JsonObject();
json.EmitCompact = false;

int timeoutMs = 2000;
int 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.
    Debug.WriteLine(sb.LastErrorText);
    return;
}

// Examine the matches:
Debug.WriteLine(json.Emit());

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

Chilkat.StringBuilder sbTemp = new Chilkat.StringBuilder();

int 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 = i + 1;
}

// The JSON now has replacement strings:
Debug.WriteLine(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.
success = sb.RegexReplace(json);
if (success == false) {
    Debug.WriteLine(sb.LastErrorText);
    return;
}

Debug.WriteLine("Result after doing replacements:");
Debug.WriteLine(sb.GetAsString());

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