Ruby UUID

How to generate a standard UUID (typically v4) in Ruby, using the standard library or a widely used package.

Code

app.rb

require 'securerandom'

SecureRandom.uuid
# => "3f2a9c8b-4d1e-4a7b-9c2d-1e2f3a4b5c6d"

Most languages provide v4 (random) out of the box, while v7 or ULID may require a separate library.