JavaScript

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

JavaScript

var success = false;

success = false;

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

var sb = new CkStringBuilder();
sb.Append(subject);

var json = new CkJsonObject();
json.EmitCompact = false;

var 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.
    console.log(sb.LastErrorText);
    return;
}

// Examine the matches:
console.log(json.Emit());

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

var sbTemp = new 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 = i+1;
}

// The JSON now has replacement strings:
console.log(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) {
    console.log(sb.LastErrorText);
    return;
}

console.log("Result after doing replacements:");
console.log(sb.GetAsString());

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