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

C#

bool 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 $$$$