Question

我试图创建一个莫尔斯解码器。它用他们的摩尔斯代码替换拉丁字母。字母之间有一个空格，字之间有三个空格。

def decodeMorse(morseCode)
morse_dict = {
    "a" => ".-","b" => "-...","c" => "-.-.","d" => "-..","e" => ".","f" => "..-.","g" => "--.","h" => "....","i" => "..","j" => ".---","k" => "-.-","l" => ".-..","m" => "--","n" => "-.","o" => "---","p" => ".--.","q" => "--.-","r" => ".-.","s" => "...","t" => "-","u" => "..-","v" => "...-","w" => ".--","x" => "-..-","y" => "-.--","z" => "--.."," " => " ","1" => ".----","2" => "..---","3" => "...--","4" => "....-","5" => ".....","6" => "-....","7" => "--...","8" => "---..","9" => "----.","0" => "-----"
}

wordList = morseCode.split(" ")

wordList.each do |word|
  word = word.downcase
  word.split("").each do |letter|
    a = ' ' + morse_dict[letter].to_s + ' '
    word.gsub! letter a
  end
end

sentence = wordList.join(' ')

return sentence.lstrip

end

puts decodeMorse("Example from description")

然后我收到了这个错误：

NoMethodError: undefined method `letter' for main:Object
    from codewars.rb:12:in `block (2 levels) in decodeMorse'
    from codewars.rb:10:in `each'
    from codewars.rb:10:in `block in decodeMorse'
    from codewars.rb:8:in `each'
    from codewars.rb:8:in `decodeMorse'

有什么问题？

Answer 1

问题在于：

word.gsub! letter a

它正在从右向左解释，因为letter和a之间没有逗号，它被视为letter(a)函数调用。您希望将letter和a作为参数传递给函数调用⇒用逗号分隔：

#                ⇓ HERE
word.gsub! letter, a

BTW，gsub可能会将哈希作为第二个参数进行替换：

word.gsub(/./, morse_dict)

会将所有字母更改为其莫尔斯代表。要处理空格，可以使用gsub来阻止空格：

word.gsub(/./) { |l| " #{morse_dict[l]} " }.squeeze(' ')

Ruby Morse解码器

1 个答案: