生成一个 7 位的随机数

Question

How can I produce a random number in a range from 1 million to 10 million?

rand(10) works, I tried rand(1..10) and that didn't work.

Answer 1

取您的基数 1,000,000 并添加一个从 0 到您的最大值的随机数 - 起始数：

 1_000_000 + Random.rand(10_000_000 - 1_000_000) #=> 3084592

Answer 2

这是一个实例方法：

puts Random.new.rand(1_000_000..10_000_000-1) 

Answer 3

我发现这更具可读性：

7.times.map { rand(1..9) }.join.to_i

Answer 4

或者，如果性能不是问题并且您不想计算零：

(0...7).map { |i| rand((i == 0 ? 1 : 0)..9) }.join.to_i

Answer 5

This will generate a random number between 1,000,000 and 9,999,999.

rand(10_000_000-1_000_000)+1_000_000

This works in 1.8.7 without any gems(backports, etc).

Answer 6

You can do this by following simple way.

rand(10 ** 6...10 ** 7 - 1)  # range between 1000000 to 9999999 )
>> 1729679

rand(10 ** 6...10 ** 7 - 1)
>> 9789151

rand(10 ** 6...10 ** 7 - 1)
>> 8989718

Hope this will help you.

Answer 7

Another option with ruby 1.8.7 compatibility:

rand(9999999999).to_s.center(10, rand(9).to_s).to_i