Xbase++ Requires Chilkat v11.1.0+

Regular Expression with Multiple Matches and Named Capture Groups

See more Regular Expressions Examples

Demonstrates regular expressions with named capture groups and multiple matches. Xbase++

LOCAL nSuccess
LOCAL oSb
LOCAL nCrlf
LOCAL cPattern
LOCAL oJson
LOCAL nTimeoutMs
LOCAL nNumMatches
LOCAL nIdx_first
LOCAL nIdx_last
LOCAL i
LOCAL nMatchCount

nSuccess := 0

oSb := CreateObject("Chilkat.StringBuilder")
nCrlf := 1
oSb:AppendLine("Name: John Smith", nCrlf)
oSb:AppendLine("Name: Jack Johnson", nCrlf)
oSb:AppendLine("Name: Mary Adams", nCrlf)

? oSb:GetAsString()

//  We have the following string:
//  Name: John Smith
//  Name: Jack Johnson
//  Name: Mary Adams

cPattern := "Name:\s+(?<first>\w+)\s+(?<last>\w+)"
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()

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

//  {
//    "named": {
//      "first": 1,
//      "last": 2
//    },
//    "match": [
//      {
//        "group": [
//          {
//            "cap": "Name: John Smith",
//            "idx": 0,
//            "len": 16
//          },
//          {
//            "cap": "John",
//            "idx": 6,
//            "len": 4
//          },
//          {
//            "cap": "Smith",
//            "idx": 11,
//            "len": 5
//          }
//        ]
//      },
//      {
//        "group": [
//          {
//            "cap": "Name: Jack Johnson",
//            "idx": 18,
//            "len": 18
//          },
//          {
//            "cap": "Jack",
//            "idx": 24,
//            "len": 4
//          },
//          {
//            "cap": "Johnson",
//            "idx": 29,
//            "len": 7
//          }
//        ]
//      },
//      {
//        "group": [
//          {
//            "cap": "Name: Mary Adams",
//            "idx": 38,
//            "len": 16
//          },
//          {
//            "cap": "Mary",
//            "idx": 44,
//            "len": 4
//          },
//          {
//            "cap": "Adams",
//            "idx": 49,
//            "len": 5
//          }
//        ]
//      }
//    ]
//  }

//  The capture group index is obtained by looking up the name in the JSON result.
//  For example:

nIdx_first := oJson:IntOf("named.first")
nIdx_last := oJson:IntOf("named.last")

i := 0
nMatchCount := oJson:SizeOfArray("match")
DO WHILE i < nMatchCount
    ? "Match " + Str(i + 1) + ":"
    oJson:I := i

    oJson:J := nIdx_first
    ? "first: " + oJson:StringOf("match[i].group[j].cap")

    oJson:J := nIdx_last
    ? "first: " + oJson:StringOf("match[i].group[j].cap")

    ? ""
    i := i + 1
ENDDO

//  Output is: 

//  Match 1:
//  first: John
//  first: Smith
//  
//  Match 2:
//  first: Jack
//  first: Johnson
//  
//  Match 3:
//  first: Mary
//  first: Adams

oSb:destroy()
oJson:destroy()