On May 18, Craig Moynes/Markham/IBM said:
>I looked through my book (perl nutshell) and PP has not arrived yet, so I
>will ask here.
>
>I have an number that needs to be rounded to the nearest whole number.
>This is my solution:
Timothy Kimball has a good solution, but I have a generalization:
# $rounded = round($num); # integer
# $rounded = round($num,2); # to hundredth's place
# $rounded = round($num,-1); # to ten's place
sub round {
my ($x, $p) = @_;
$x ||= 0;
$p ||= 0;
(1,-1)[$x < 0] * int( abs($x) * 10**$p + .5 ) / 10**$p;
}
This technique allows you to round to some place to the left OR right of
the decimal point. It uses a very simple method: it brings the digit in
the place you want to round IMMEDIATELY to the left of the decimal point:
v
round(10234.543, -3);
10234.543
1023.4543
102.34543
It pretends the number is positive (but knows to multiply by -1 if it was
negative). Then it adds .5 and takes the integer value. Then, it moves
the digits back to where they started.
102.34543
+ .5
----------
102.84543
102
10200
--
Jeff "japhy" Pinyan [EMAIL PROTECTED] http://www.pobox.com/~japhy/
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