Ruby自定义字符串排序 [英] Ruby custom string sort

问题描述

输入字符串:

1654AaBcDddeeFF 

输出字符串:

1456acddeeABDFF

我尝试的代码:

test_array = []
'1654AaBcDddeeFF'.each_byte do |char|
  test_array << char
end

test_array.sort.pack('C*')
# => 1456ABDFFacddee

但是我想最后看看大写字母.

But I would like to see the upper case characters at last.

推荐答案

由于@hirolau已经被接受为swapcase，因此我提供了另一种选择(尽管我更喜欢他的回答). las，@ Stefan发现了一个漏洞，但提出了一个不错的解决方法:

Since @hirolau's already taken swapcase, I offered an alternative (even though I prefer his answer). Alas, @Stefan identified a flaw, but suggested a nice fix:

str = '1654AaBcDddeeFF'

order_array = [*'0'..'9',*'a'..'z',*'A'..'Z']
str.each_char.sort_by { |c| order_array.index(c) }.join
  #=> "1456acdeABDF" 

(我只是一个抄写员.)

(I am a mere scribe.)

此方法的一个优点是您可以将其用于其他订购.例如，如果:

One advantage of this approach is that you could use it for other orderings. For example, if:

str = '16?54!AaBcDdde,eFF'

，您还想在开始时将字符'！?'分组，可以这样写:

and you also wanted to group the characters `'!?,' at the beginning, in that order, you could write:

order_array = [*'!?,'.chars,*'0'..'9',*'a'..'z',*'A'..'Z']
str.each_char.sort_by { |c| order_array.index(c) }.join
  #=> "!?,1456acdeABDF" 

我们可以通过将order_array转换为哈希来提高效率.对于最后一个示例:

We can make this a bit more efficient by converting order_array to a hash. For the last example:

order_hash = Hash[order_array.each_with_index.to_a]

然后:

str.each_char.sort_by { |c| order_hash[c] }.join
  # => "!?,1456acddeeABDFF"

这篇关于Ruby自定义字符串排序的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！