Xbase++ 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

Xbase++

LOCAL nSuccess
LOCAL cPattern
LOCAL oSb
LOCAL nCrlf
LOCAL oJson
LOCAL nTimeoutMs
LOCAL nNumMatches
LOCAL cCap
LOCAL i
LOCAL nMatchCount
LOCAL j
LOCAL nNumCaptureGroups

nSuccess := 0

cPattern := "Name:\s+(\w+)\s+(\w+),\s+Email:\s+(\S+)"

oSb := CreateObject("Chilkat.StringBuilder")
nCrlf := 1
oSb:AppendLine("Name: John Smith, Email: john.smith@example.com", nCrlf)
oSb:AppendLine("Name: Jack Johnson, Email: jack.johnson@example.com", nCrlf)
oSb:AppendLine("Name: Mary Adams, Email: mary.adams@example.com", nCrlf)

? oSb: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

oJson := CreateObject("Chilkat.JsonObject")
oJson:EmitCompact := 0

nTimeoutMs := 2000
nNumMatches := oSb:RegexMatch(cPattern, oJson, nTimeoutMs)
IF (nNumMatches < 0)
    //  Probably an error in the regular expression.
    //  Suggestion: Use AI to help create and/or diagnose regular expressions.
    ? oSb:LastErrorText
    oSb:destroy()
    oJson:destroy()
    RETURN
ENDIF

//  Examine the matches:
? oJson: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
nMatchCount := oJson:SizeOfArray("match")
DO WHILE i < nMatchCount
    ? "Match " + Str(i + 1) + ":"
    oJson:I := i
    j := 0
    nNumCaptureGroups := oJson:SizeOfArray("match[i].group")
    DO WHILE j < nNumCaptureGroups
        oJson:J := j
        cCap := oJson:StringOf("match[i].group[j].cap")
        ? Str(j) + ": " + cCap
        j := j + 1
    ENDDO
    i := i + 1
ENDDO

//  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

oSb:destroy()
oJson:destroy()