Classic ASP

Regular Expression with Capture Groups

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

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"

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"

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.

Chilkat Classic ASP Downloads

Download Chilkat for Classic ASP

Classic ASP

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
success = 0

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

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

set json = Server.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.
    Response.Write "<pre>" & Server.HTMLEncode( sb.LastErrorText) & "</pre>"
    Response.End
End If

' Examine the matches:
Response.Write "<pre>" & Server.HTMLEncode( json.Emit()) & "</pre>"

' 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
    Response.Write "<pre>" & Server.HTMLEncode( "Match " & i + 1 & ":") & "</pre>"
    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")
        Response.Write "<pre>" & Server.HTMLEncode( j & ": " & cap) & "</pre>"
        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

%>
</body>
</html>