Ruby 计数到给定值的数组

Question

Trying to do something like:

def action(number)

nums = [1...number]
code_here...

end

Do I need to write up a "count" snippet for this to work? Or is something similar to what I'm trying to do possible?

Answer 1

There's another option to use enumerators:

1.upto(10).to_a #=> [1,2,3,4,5,6,7,8,9,10]

There are quite a few useful ones. For example, if you only need every other number up to certain number you can use:

0.step(100, 2).to_a #=> [0,2,4,6,8,..., 98,100]

Another option would be to use Array constructor:

Array.new(10) { |i| i + 1 } #=> [1,2,3,4,5,6,7,8,9,10]

which is a bit more verbose, but gives you much more freedom:

Array.new(10) { |i| 2 ** i } #=> [1,2,4,8,16,32,64,256,512]

Answer 2

There are two solutions for this as following:

If you want to add number in the array than:

nums = [*1..number]
# or
nums = (1..number).to_a

Ignoring last number than:

nums = [*1...number]
# or
nums = (1...number).to_a