When the argument is an Integer or a
Bignum, it returns a random integer
greater than or equal to zero and less than the argument. Unlike Random.rand, when the argument is a negative
integer or zero, it raises an ArgumentError.
When the argument is a Float, it returns
a random floating point number between 0.0 and max, including 0.0
and excluding max.
When the argument limit is a Range, it returns a random number where
range.member?(number) == true.
prng.rand(5..9)#=> one of [5, 6, 7, 8, 9]prng.rand(5...9)#=> one of [5, 6, 7, 8]prng.rand(5.0..9.0)#=> between 5.0 and 9.0, including 9.0prng.rand(5.0...9.0)#=> between 5.0 and 9.0, excluding 9.0
begin/end of the range have to have subtract and add methods.
