How to get random number in ruby?

Without an argument

Returns number between 0.0 - 1.0, including 0.0 and excluding 1.0.

3.1.4 :001 > rand
#=> 0.43273184407039833

With max limit

Returns a random integer greater than or equal to 0 and less than max.to_i.abs.

3.1.4 :002 > rand(10)
#=> 4

With a range

Returns a random integer number between the provided range including both the numbers.

3.1.4 :003 > rand(1..10)
#=> 8