Perl 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. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

my $success = 0;

my $sb = Chilkat2::StringBuilder->new;
my $crlf = 1;
$sb->AppendLine('Name: John Smith', $crlf);
$sb->AppendLine('Name: Jack Johnson', $crlf);
$sb->AppendLine('Name: Mary Adams', $crlf);

print $sb->GetAsString(), "\n";

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

my $pattern = 'Name:\s+(?<first>\w+)\s+(?<last>\w+)';
my $json = Chilkat2::JsonObject->new;
$json->EmitCompact(0);

my $timeoutMs = 2000;
my $numMatches = $sb->RegexMatch($pattern, $json, $timeoutMs);
if ($numMatches < 0) {
    # Probably an error in the regular expression.
    # Suggestion: Use AI to help create and/or diagnose regular expressions.
    print $sb->LastErrorText, "\n";
    exit;
}

# Examine the matches:
print $json->Emit(), "\n";

# 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:

my $idx_first = $json->IntOf('named.first');
my $idx_last = $json->IntOf('named.last');

my $i = 0;
my $matchCount = $json->SizeOfArray('match');
while ($i < $matchCount) {
    print 'Match ', ($i + 1), ":\n";
    $json->I($i);

    $json->J($idx_first);
    print 'first: ', $json->StringOf('match[i].group[j].cap'), "\n";

    $json->J($idx_last);
    print 'first: ', $json->StringOf('match[i].group[j].cap'), "\n";

    print "\n";
    $i = $i + 1;
}

# Output is:

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