Perl

Regular Expression with Multiple Matches and Named Capture Groups

See more Regular Expressions Examples

Demonstrates regular expressions with named capture groups and multiple matches. Perl

use chilkat();

$success = 0;

$sb = chilkat::CkStringBuilder->new();
$crlf = 1;
$sb->AppendLine("Name: John Smith",$crlf);
$sb->AppendLine("Name: Jack Johnson",$crlf);
$sb->AppendLine("Name: Mary Adams",$crlf);

print $sb->getAsString() . "\r\n";

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

$pattern = "Name:\\s+(?<first>\\w+)\\s+(?<last>\\w+)";
$json = chilkat::CkJsonObject->new();
$json->put_EmitCompact(0);

$timeoutMs = 2000;
$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() . "\r\n";
    exit;
}

# Examine the matches:
print $json->emit() . "\r\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:

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

$i = 0;
$matchCount = $json->SizeOfArray("match");
while ($i < $matchCount) {
    print "Match " . ($i + 1) . ":" . "\r\n";
    $json->put_I($i);

    $json->put_J($idx_first);
    print "first: " . $json->stringOf("match[i].group[j].cap") . "\r\n";

    $json->put_J($idx_last);
    print "first: " . $json->stringOf("match[i].group[j].cap") . "\r\n";

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

# Output is: 

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