in reply to Re: need regular expression
in thread need regular expression

This formula is simpler than the one earlier. The main insight here is to avoid strings; it is better to use arithmetic addition to construct the 'year' string (i.e. 20xx) . 
for ( my @dates = qw( 4-10-31 14-11-31 ) ) {
        s/
        ^
        (\d{1,2})
        ((?:-\d{1,2}){2})
        $
        /(2000+$1).$+/xe
        and print;
}

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Re^3: need regular expression
by Perl Mouse (Chaplain) on Nov 02, 2005 at 11:13 UTC
    I prefer to use strings - in that case, it becomes easy to deal with 3 or 4 digit years as well: 
        my @dates = qw /4-10-31 14-11-31 1979-10-10/;
    for (@dates) {
        s/(\d+)/substr("2000", 0, -length($1)).$1/e;
        print "$_\n";
    }
    __END__
    2004-10-31
    2014-11-31
    1979-10-10

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    Perl --((8:>*
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