As with many things in Ruby, generating a random number is quite straight forward. The rand function gives you a random (enough) floating-point number between 0 and 1 (up to but not including 1). You can pass a parameter to specify the settings for your random number.

You can try any of this code online at https://repl.it.

Ways to Call rand

rand

The rand function with no parameters returns a floating-point number from 0 up to 1 (but not including 1).

rand(x)

rand(x) will give you an integer (whole number) from 0 up to x (but not including x). So rand(6) will give you integers in the range of 0 and 5.
rand(3) can return either 0, 1, or 2.
rand(1) will only give you 0.
rand(0)just gives you a floating-point between 0 and 1, the same as using no parameters, because 0 is not a range.

Following is a bunch of random integers, done many times over.

Seeing as how everything starts at 0, if you'd like to get random six-sided dice roll, you'd need to get random numbers in the range of 1 to 6 (inclusive). One way to do that is to get a random number between 0 and 5 and add 1!

rand(6) + 1 (A Dice Roll)

rand(x..y)

Ruby allows us to use a range as a parameter to the random function.
rand(x..y) (inclusive of y) and rand(x...y) (not inclusive of y)

rand(0.8...1.2)

Finally, you can get random floating-point numbers in a range if you specify floating point numbers as the range parameters.

These are the ways of getting basic random numbers (non-seeded) in Ruby. Thanks for reading.