Delphi ActiveX Requires Chilkat v11.1.0+

Regular Expression with Multiple Matches and Capture Groups

See more Regular Expressions Examples

Demonstrates a regular expression with multiple matches and capture groups for each match.

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

Delphi ActiveX

var
success: Integer;
pattern: WideString;
sb: TChilkatStringBuilder;
crlf: Integer;
json: TChilkatJsonObject;
timeoutMs: Integer;
numMatches: Integer;
cap: WideString;
i: Integer;
matchCount: Integer;
j: Integer;
numCaptureGroups: Integer;

begin
success := 0;

pattern := 'Name:\\s+(\\w+)\\s+(\\w+),\\s+Email:\\s+(\\S+)';

sb := TChilkatStringBuilder.Create(Self);
crlf := 1;
sb.AppendLine('Name: John Smith, Email: john.smith@example.com',crlf);
sb.AppendLine('Name: Jack Johnson, Email: jack.johnson@example.com',crlf);
sb.AppendLine('Name: Mary Adams, Email: mary.adams@example.com',crlf);

Memo1.Lines.Add(sb.GetAsString());

//  We have the following string:
//  Name: John Smith, Email: john.smith@example.com
//  Name: Jack Johnson, Email: jack.johnson@example.com
//  Name: Mary Adams, Email: mary.adams@example.com

json := TChilkatJsonObject.Create(Self);
json.EmitCompact := 0;

timeoutMs := 2000;
numMatches := sb.RegexMatch(pattern,json.ControlInterface,timeoutMs);
if (numMatches < 0) then
  begin
    //  Probably an error in the regular expression.
    //  Suggestion: Use AI to help create and/or diagnose regular expressions.
    Memo1.Lines.Add(sb.LastErrorText);
    Exit;
  end;

//  Examine the matches:
Memo1.Lines.Add(json.Emit());

//  This is the JSON with the match information.
//  See the JSON parsing code below to get the matched capture group values.

//  {
//    "match": [
//      {
//        "group": [
//          {
//            "cap": "Name: John Smith, Email: john.smith@example.com",
//            "idx": 0,
//            "len": 47
//          },
//          {
//            "cap": "John",
//            "idx": 6,
//            "len": 4
//          },
//          {
//            "cap": "Smith",
//            "idx": 11,
//            "len": 5
//          },
//          {
//            "cap": "john.smith@example.com",
//            "idx": 25,
//            "len": 22
//          }
//        ]
//      },
//      {
//        "group": [
//          {
//            "cap": "Name: Jack Johnson, Email: jack.johnson@example.com",
//            "idx": 49,
//            "len": 51
//          },
//          {
//            "cap": "Jack",
//            "idx": 55,
//            "len": 4
//          },
//          {
//            "cap": "Johnson",
//            "idx": 60,
//            "len": 7
//          },
//          {
//            "cap": "jack.johnson@example.com",
//            "idx": 76,
//            "len": 24
//          }
//        ]
//      },
//      {
//        "group": [
//          {
//            "cap": "Name: Mary Adams, Email: mary.adams@example.com",
//            "idx": 102,
//            "len": 47
//          },
//          {
//            "cap": "Mary",
//            "idx": 108,
//            "len": 4
//          },
//          {
//            "cap": "Adams",
//            "idx": 113,
//            "len": 5
//          },
//          {
//            "cap": "mary.adams@example.com",
//            "idx": 127,
//            "len": 22
//          }
//        ]
//      }
//    ]
//  }

//  Important:  Capture group 0 always contains the entire match — that is, the portion of the input string that matches the full regular expression.

i := 0;
matchCount := json.SizeOfArray('match');
while i < matchCount do
  begin
    Memo1.Lines.Add('Match ' + IntToStr(i + 1) + ':');
    json.I := i;
    j := 0;
    numCaptureGroups := json.SizeOfArray('match[i].group');
    while j < numCaptureGroups do
      begin
        json.J := j;
        cap := json.StringOf('match[i].group[j].cap');
        Memo1.Lines.Add(IntToStr(j) + ': ' + cap);
        j := j + 1;
      end;

    i := i + 1;
  end;

//  Capture group 0 always contains the entire match — that is, the portion of the input string that matches the full regular expression.

//  Output

//  Match 1:
//  0: Name: John Smith, Email: john.smith@example.com
//  1: John
//  2: Smith
//  3: john.smith@example.com
//  Match 2:
//  0: Name: Jack Johnson, Email: jack.johnson@example.com
//  1: Jack
//  2: Johnson
//  3: jack.johnson@example.com
//  Match 3:
//  0: Name: Mary Adams, Email: mary.adams@example.com
//  1: Mary
//  2: Adams
//  3: mary.adams@example.com