Xojo Plugin

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

Xojo Plugin

Dim success As Boolean
success = False

Dim pattern As String
pattern = "Name:\s+(\w+)\s+(\w+),\s+Email:\s+(\S+)"

Dim sb As New Chilkat.StringBuilder
Dim crlf As Boolean
crlf = True
success = sb.AppendLine("Name: John Smith, Email: john.smith@example.com",crlf)
success = sb.AppendLine("Name: Jack Johnson, Email: jack.johnson@example.com",crlf)
success = sb.AppendLine("Name: Mary Adams, Email: mary.adams@example.com",crlf)

System.DebugLog(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

Dim json As New Chilkat.JsonObject
json.EmitCompact = False

Dim timeoutMs As Int32
timeoutMs = 2000
Dim numMatches As Int32
numMatches = sb.RegexMatch(pattern,json,timeoutMs)
If (numMatches < 0) Then
    // Probably an error in the regular expression.
    // Suggestion: Use AI to help create and/or diagnose regular expressions.
    System.DebugLog(sb.LastErrorText)
    Return
End If

// Examine the matches:
System.DebugLog(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.

Dim cap As String
Dim i As Int32
i = 0
Dim matchCount As Int32
matchCount = json.SizeOfArray("match")
While i < matchCount
    System.DebugLog("Match " + Str(i + 1) + ":")
    json.I = i
    Dim j As Int32
    j = 0
    Dim numCaptureGroups As Int32
    numCaptureGroups = json.SizeOfArray("match[i].group")
    While j < numCaptureGroups
        json.J = j
        cap = json.StringOf("match[i].group[j].cap")
        System.DebugLog(Str(j) + ": " + cap)
        j = j + 1
    Wend
    i = i + 1
Wend

// 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.co