如何通過陣列從最後一個元素迭代在Ruby中

Question

可能重複：
How to iterate through an array starting from the last element? (Ruby)

我試圖遍歷反向列表，但我一直沒能想辦法。

這裏是我的代碼：

#!/usr/bin/ruby 
presidents = ["Ford", "Carter", "Reagan", "Bush1", "Clinton", "Bush2"] 

for ss in -presidents.length...0 
    print ": ", presidents[ss], "\n"; 
end 

Answer 1

使用reverse_each

presidents = ["Ford", "Carter", "Reagan", "Bush1", "Clinton", "Bush2"] 
presidents.reverse_each { |president| p president } 

Answer 2

presidents = ["Ford", "Carter", "Reagan", "Bush1", "Clinton", "Bush2"] 

presidents.reverse.each do |president| 
    puts president 
end 

Answer 3

這裏是另一種方式

(presidents.length-1).step(0,-1) {|i| p presidents[i]}