How to generate a random string in Ruby

 

I'm currently generating an 8-character pseudo-random uppercase string for "A" .. "Z": 

value = ""; 8.times{value  << (65 + rand(25)).chr}

but it doesn't look clean, and it can't be passed as an argument since it isn't a single statement. To get a mixed-case string "a" .. "z" plus "A" .. "Z", I changed it to: 

value = ""; 8.times{value << ((rand(2)==1?65:97) + rand(25)).chr}

but it looks like trash.

Does anyone have a better method? 

(0...8).map { (65 + rand(26)).chr }.join

I spend too much time golfing. 

(0...50).map { ('a'..'z').to_a[rand(26)] }.join

And a last one that's even more confusing, but more flexible and wastes fewer cycles: 

o = [('a'..'z'), ('A'..'Z')].map(&:to_a).flatten
string = (0...50).map { o[rand(o.length)] }.join

Why not use SecureRandom? 

require 'securerandom'
random_string = SecureRandom.hex

# outputs: 5b5cd0da3121fc53b4bc84d0c8af2e81 (i.e. 32 chars of 0..9, a..f)

SecureRandom also has methods for:

  • base64
  • random_bytes
  • random_number

    • see: http://ruby-doc.org/stdlib-1.9.2/libdoc/securerandom/rdoc/SecureRandom.html

    I use this for generating random URL friendly strings with a guaranteed maximum length: 

    rand(36**length).to_s(36)

    It generates random strings of lowercase az and 0-9. It's not very customizable but it's short and clean.

    链接地址: http://www.djcxy.com/p/20590.html

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