Ruby 有随机数生成器类吗？ [复制]

Question

可能重复：
How to get a random number in Ruby?

我只是好奇，但是 Ruby 是否有一个专门用于生成随机数的类，比如 Java 的 java.util.Random 类，或者是 Ruby 的所有 rand 方法？

Answer 1

内核中有一个rand方法:)

API Docs

rand(max=0) => number
Converts max to an integer using max1 = max.to_i.abs. If the result is zero, returns a pseudorandom floating point number greater than or equal to 0.0 and less than 1.0. Otherwise, returns a pseudorandom integer greater than or equal to zero and less than max1. Kernel::srand may be used to ensure repeatable sequences of random numbers between different runs of the program. Ruby currently uses a modified Mersenne Twister with a period of 2**19937-1.

   srand 1234                 #=> 0
   [ rand,  rand ]            #=> [0.191519450163469, 0.49766366626136]
   [ rand(10), rand(1000) ]   #=> [6, 817]
   srand 1234                 #=> 1234
   [ rand,  rand ]            #=> [0.191519450163469, 0.49766366626136]