Ruby，如何產生隨機亂數？！

Ruby，如何產生隨機亂數？！

Method 1:

require 'securerandom'  #Ruby 2.0 included!
random_string = SecureRandom.hex

# outputs: 5b5cd0da3121fc53b4bc84d0c8af2e81

SecureRandom also has methods for:

• base64
• hex
• random_bytes
• random_number

Method 2:

require 'securerandom'
s = SecureRandom.urlsafe_base64(20)