ruby - Ruby 中的随机数生成器问题

Question

我在这里的意图只是用数字从 1 到 1 到 1000 之间的随机数填充一个数组。但是，在重复运行此代码（大约 50 次）之后，我得到的最高数字是 120，并且只有两次超过 100。我的大多数数组都在 0 到 60 之间。这种行为对我来说似乎很奇怪。难道我做错了什么？

my_array = []
i = 0
while i <= rand(1000)
    my_array << i 
    i += 1  
end

puts my_array.count
puts my_array

Answer 1

您的功能已损坏，因为您正在检查随机数。做这个：

(0..1000).collect{ rand(1000) }

这将返回一个包含一千个随机数的数组。

或者，更接近您的代码：

my_array = []
i = 0
while i <= 1000
    my_array << rand(1000) 
    i += 1  
end

根据评论，您想要的是：

(1..rand(1000))

(1..rand(1000)).to_a

第一个结果是一个“更容易携带”的范围，第二个结果是填充数组。

（编辑）注意：

(1..10)是包容的 -(1..10).to_a == [1,2,3,4,5,6,7,8,9,10]

(1...10) is partially exclusive - (1...10).to_a == [1,2,3,4,5,6,7,8,9] - it does not include the end of the array, but still includes the beginning.

Answer 2

It sounds like you want:

(1...rand(1000)).to_a

Answer 3

Additionally, I have amended my code to reflect what I was trying to accomplish initially. My problem was that every time I looped through my code I generated a new random number. Because of this, as 'i' incremented toward 1000 it became more and more likely that a random number would be generated that was lower than 'i'. My fix, while not as elegant as the solution above that I accepted, was to store the random number in a variable, BEFORE attempting to use it in a loop. Thanks again. Here is the amended code:

my_array = []
i = 0
g = rand(1000)
while i <= g
    my_array << i 
    i += 1  
end

puts my_array.count
puts my_array