有沒有一種更慣用的方式來表達循環中還剩下多少次迭代？

Question

我正在寫這樣的Ruby循環：

iterations = 10

until iterations == 0
    unless iterations == 1
      puts "#{iterations} iterations until done"
    else
      puts "#{iterations} iteration until done"
    end

    iterations -= 1
end

puts "Done"

我想知道是否還有更多“ Ruby方式”來優化/編寫此代碼。 有人有什么想法嗎？

Answer 1

10.downto(1) do |iteration|
  puts "#{iteration} iteration#{'s' if iteration > 1} until done"
end
puts 'Done'

Answer 2

require 'active_support/inflector'

10.downto(1).each { |i| puts "#{i} #{'iteration'.pluralize(i)} until done" }
puts 'Done'

Answer 3

用范圍對象向上計數

如果不需要倒數，則可以通過迭代Range對象進一步簡化。 例如：

(1..10).each { |i| puts "#{i} iterations completed" }

這將打印：

1 iterations completed
2 iterations completed
3 iterations completed
4 iterations completed
5 iterations completed
6 iterations completed
7 iterations completed
8 iterations completed
9 iterations completed
10 iterations completed

反轉范圍

如果您已經有一個Range對象，並且想倒計時而不必調用Integer＃downto，則也可以反轉Range。 例如：

(1..10).to_a.reverse.each  { |i| puts i }