Raku Books / Using Raku / Numbers / Random numbers
32. Generating random numbers
Generate a random number between 0 and N.
Use the rand method, which returns a random number
between 0 and the value of its invocant:
say 1.rand; # between 0 and 1
say 2.5.rand; # between 0 and 2.5
say pi.rand; # between 0 and 3.14…The rand method is defined in the Cool
class, which is the base class for the Int,
Num, and Rat types. It always returns a
floating-point value of the Num data type.
To generate random integer numbers, call the Int
method:
say 10.rand.Int; # Either 0, or 1, 2, 3, 4, 5, 6, 7, 8, or 9 but not 10The srand function initializes the random numbers
generator. The function expects an integer argument:
srand(1);After setting the seed, the rand method starts
generating numbers in the same sequence.
srand(1);
my $a = 10.rand;
srand(1);
my $b = 10.rand;
say $a == $b; # True↻ Runs in Rakudo; the in-browser engine (Raku++) doesn’t support this program yet — see the expected output above.