FAQ 4.11 How do I get a random number between X and Y?
am 17.02.2005 06:03:01 von brian d foyThis message is one of several periodic postings to comp.lang.perl.misc
intended to make it easier for perl programmers to find answers to
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4.11: How do I get a random number between X and Y?
"rand($x)" returns a number such that "0 <= rand($x) < $x". Thus what
you want to have perl figure out is a random number in the range from 0
to the difference between your *X* and *Y*.
That is, to get a number between 10 and 15, inclusive, you want a random
number between 0 and 5 that you can then add to 10.
my $number = 10 + int rand( 15-10+1 );
Hence you derive the following simple function to abstract that. It
selects a random integer between the two given integers (inclusive), For
example: "random_int_in(50,120)".
sub random_int_in ($$) {
my($min, $max) = @_;
# Assumes that the two arguments are integers themselves!
return $min if $min == $max;
($min, $max) = ($max, $min) if $min > $max;
return $min + int rand(1 + $max - $min);
}
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