ramprasad27 has asked for the wisdom of the Perl Monks concerning the following question:

Hi , 
my $str = 'ban go ban';
my $count =()= ($str =~ /ban/g);
print $count;
my $count_again = ($str =~ /ban/g);
print "\n$count_again";

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can somebody explain me the difference in output

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Re: regexp match count
by ikegami (Patriarch) on Oct 09, 2011 at 05:44 UTC

    The first match operator is called in list context. m//g in list context returns a list of all the captured strings or a list of all the matched strings if there are no captures.

    The second match operator is called in scalar context. m// (with or without 'g') in scalar context returns true if a match occurred or false otherwise.

    perlop

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      Thnk you. It answered my doubt
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Re: regexp match count
by eyepopslikeamosquito (Archbishop) on Oct 09, 2011 at 06:58 UTC 

    my $count =()= ($str =~ /ban/g);

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    This is the famous =()= goatse "secret operator", nicely explained here (along with Perl's other "secret operators").

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Re: regexp match count
by davido (Cardinal) on Oct 09, 2011 at 05:16 UTC

    This should explain it.

    say( 
    '$count = () = ( wantarray() ) gives ',
    ( $count = () = ( wantarray() ) ) 
    ? "List" : "Scalar", 
    " context to wantarray()." 
);


say(
    '$count = ( wantarray() ) gives ',
    ( $count = ( wantarray() ) ) 
    ? "List" : "Scalar", 
    " context to wantarray()." 
);

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    The output:

    $count = () = ( wantarray() ) gives List context to wantarray().
$count = ( wantarray() ) gives Scalar context to wantarray().

    [download]

    Dave

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