rand
Returns a pseudo-random floating-point number.
Returns a pseudo-random floating-point number greater than or equal to
0 and less than EXPR (or 1 if omitted). If EXPR evaluates to zero,
1.0 is used instead. Uses the interpreter’s StdRng state, which
can be seeded via srand. Not suitable for cryptographic purposes.
Synopsis
my $r = rand; # 0 <= $r < 1
my $r = rand(10); # 0 <= $r < 10
my $r = rand($n);