(PowerBuilder) 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

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.

Note: This example requires Chilkat v11.1.0 or greater.

For more information, see https://www.chilkatsoft.com/chilkat_pcre2.asp

Chilkat ActiveX Downloads

ActiveX for 32-bit and 64-bit Windows

integer li_rc
integer li_Success
string ls_Subject
string ls_Pattern
oleobject loo_Sb
oleobject loo_Json
integer li_TimeoutMs
integer li_NumMatches
string ls_Cap
integer i
integer li_MatchCount
integer j
integer li_NumCaptureGroups

li_Success = 0

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

loo_Sb = create oleobject
li_rc = loo_Sb.ConnectToNewObject("Chilkat.StringBuilder")
if li_rc < 0 then
    destroy loo_Sb
    MessageBox("Error","Connecting to COM object failed")
    return
end if
loo_Sb.Append(ls_Subject)

loo_Json = create oleobject
li_rc = loo_Json.ConnectToNewObject("Chilkat.JsonObject")

loo_Json.EmitCompact = 0

li_TimeoutMs = 2000
li_NumMatches = loo_Sb.RegexMatch(ls_Pattern,loo_Json,li_TimeoutMs)
if li_NumMatches < 0 then
    // Probably an error in the regular expression.
    // Suggestion: Use AI to help create and/or diagnose regular expressions.
    Write-Debug loo_Sb.LastErrorText
    destroy loo_Sb
    destroy loo_Json
    return
end if

// Examine the matches:
Write-Debug loo_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
li_MatchCount = loo_Json.SizeOfArray("match")
do while i < li_MatchCount
    Write-Debug "Match " + string(i + 1) + ":"
    loo_Json.I = i
    j = 0
    li_NumCaptureGroups = loo_Json.SizeOfArray("match[i].group")
    do while j < li_NumCaptureGroups
        loo_Json.J = j
        ls_Cap = loo_Json.StringOf("match[i].group[j].cap")
        Write-Debug string(j) + ": " + ls_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


destroy loo_Sb
destroy loo_Json