ruby - 算法删除元音，意外结果

Question

我正在尝试构建一种从字符串中删除元音的算法。下面的代码是我到目前为止所拥有的。

def shortcut(s)
  s = s.split("")
  for i in 0..s.length - 1 do
    if ["a","e","i","o","u"].include?(s[i])
      s.delete_at(i)
    end
  end
  s.join
end


puts shortcut("hello world, we are the champions")
# => hll wrld, w r th chmpons

为什么 'o' 没有从字符串中删除？

Answer 1

通过删除一个字符，索引变得无效。

hello
  ^    before delete
01234
  v    after delete
hllo

您可以从头到尾迭代以解决它。

def shortcut(s)
  s = s.split("")
  (s.length - 1).downto(0) do |i|
    if ["a","e","i","o","u"].include?(s[i])
      s.delete_at(i)
    end
  end
  s.join
end

但更好的解决方案是使用字符串替换方法，如 String#delete , String#gsub .

"hello world, we are the champions".gsub(/[aeiou]/, '')
=> "hll wrld, w r th chmpns"