I was having trouble sleeping one night, so I decided to bore myself to sleep by coming up with a way to round a number to any decimal place without using printf(). The solution I came up with also lets you round to any place at all (like 10s, 100s, etc.)

To use this, call round() with the number you want to round, followed by a multiple of 10 describing to which place you want to round to (10 rounds to the nearest 10, .1 to the nearest 10ths, .001 to the nearest thousandth place... you get the idea).

By the way, I benchmarked this and it is marginally faster than printf().

sub round {
    my ($num, $place) = @_;
    my $r = $num / $place;

    return $r - int($r) < .5 ?
        int($r) * $place :
        (int($r) + 1) * $place;
}

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In reply to Round a Number to Any Place by reptile

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