Question

def longest_word(string)
  words = string.split
  idx = 0
  while idx < words.length
    if words[idx].length > words[idx + 1].length
      longest = words[idx]
    else
      longest = words [idx + 1]
    end
    idx += 1
  end
  return longest
end

puts(longest_word("peas rambling tattoo") == "rambling")

不断收到错误消息

longest_word.rb：5：longest_word': undefined method长度'为nil：NilClass（NoMethodError）
来自longest_word.rb：15：在''

关于为什么会发生这种情况的任何信息都会很棒

Answer 1

words.length返回元素数，但索引以0开头。

您需要(words.length - 1)

def longest_word(string)
  words = string.split
  idx = 0
  while idx < (words.length - 1)
    if words[idx].length > words[idx + 1].length
      longest = words[idx]
    else
      longest = words [idx + 1]
    end
    idx += 1
  end
  return longest
end

puts(longest_word("peas rambling tattoo") == "rambling")

您的代码不是＆＃39; rubyesk＆＃39;，我更愿意：

def longest_word(string)
  longest = ''
  string.split.each do |word|
    longest = word.length > longest.length ? word : longest
  end
  return longest
end

puts(longest_word("peas rambling tattoo") == "rambling")

或者更好：

def longest_word(string)
  longest = ''
  string.split.each do |word|
      longest = word  if word.length > longest.length 
  end
  return longest
end

puts(longest_word("peas rambling tattoo") == "rambling")

您还可以使用max_by来获取更短的代码：

def longest_word(string)
  string.split.max_by{|word| word.length}
end

puts(longest_word("peas rambling tattoo") == "rambling")

或者更短string.split.max_by(&:length)

为什么长度不被视为此代码中的方法？

1 个答案: