my @array = (5, 4, 3, 2, 1);

foreach (0 .. $#array) {
    print "$_ => $array[$_]\n";
    if ($array[$_] <= 3) {
        print "Splicing $_ => $array[$_]\n";
        splice @array, $_, 1;
    }
}

##</code><code>##

my @array = (5, 4, 3, 2, 1);

my $i = 0;
SPLICER:
while ($i < @array) {
    print "$i => $array[$i]\n";
    if ($array[$i] <= 3) {
        print "Splicing $i => $array[$i]\n";
        splice @array, $i, 1;
        next SPLICER;
    }
    $i++;
}