VBScript

Regular Expression with Capture Groups

See more Regular Expressions Examples

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

Demonstrates the following PCRE2 regular expression:

See the sample code below.

Name:\s+(\w+)\s+(\w+),\s+Email:\s+(\S+)

And apply it to this string:

Name: John Smith, Email: john.smith@example.com

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Regex Components Explained

Part	Meaning	Matched Text
"Name:"	Matches the literal text "Name:"	"Name:"
"\s+"	Matches one or more whitespace characters (spaces, tabs, etc.)	(space)
"(\w+)"	Capture Group 1: One or more word characters ("a-zA-Z0-9_")	"John"
"\s+"	More whitespace	(space)
"(\w+)"	Capture Group 2: Another word (the last name)	"Smith"
","	A literal comma	","
"\s+"	Whitespace again	(space)
"Email:"	Matches the literal "Email:"	"Email:"
"\s+"	Whitespace	(space)
"(\S+)"	Capture Group 3: One or more non-whitespace characters	"john.smith@example.com"

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Matches for Your Example String

String:

"Name: John Smith, Email: john.smith@example.com"

Regex Match Groups:

Group	Captured Value
Group 1	"John"
Group 2	"Smith"
Group 3	"john.smith@example.com"

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Notes on Character Classes

• \w matches [a-zA-Z0-9_] — so it doesn’t include punctuation like a period.
• \S matches any non-whitespace character, so it’s good for capturing an email.

VBScript

Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

success = 0

subject = "Name: John Smith, Email: john.smith@example.com"
pattern = "Name:\s+(\w+)\s+(\w+),\s+Email:\s+(\S+)"

set sb = CreateObject("Chilkat.StringBuilder")
success = sb.Append(subject)

set json = CreateObject("Chilkat.JsonObject")
json.EmitCompact = 0

timeoutMs = 2000
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.
    outFile.WriteLine(sb.LastErrorText)
    WScript.Quit
End If

' Examine the matches:
outFile.WriteLine(json.Emit())

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

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

' {
'   "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
'         }
'       ]
'     }
'   ]
' }

i = 0
matchCount = json.SizeOfArray("match")
Do While i < matchCount
    outFile.WriteLine("Match " & (i + 1) & ":")
    json.I = i
    j = 0
    numCaptureGroups = json.SizeOfArray("match[i].group")
    Do While j < numCaptureGroups
        json.J = j
        cap = json.StringOf("match[i].group[j].cap")
        outFile.WriteLine(j & ": " & cap)
        j = j + 1
    Loop
    i = i + 1
Loop

' 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

outFile.Close