將返回值傳遞給另一種方法

Question

我從一系列字母開始：

letters = %w[c s t p b l f g d m  
             y o u i h t r a e l 
             o t l a e m r s n i 
             m a y l p x s e k d]

通過它們，找到所有返回數組的組合，例如["cstp", "cstb", "cstl"] ，這是一個簡化的示例。

def combinations(letters)
  combos = letters.combination(4) 
  combos.collect do |letter_set|
    letter_set.join(",").gsub("," ,"")  
  end
end

我試圖弄清楚如何將combinations的返回值傳遞給start_wtih_letter_c 。 我是否必須通過&block這樣的代碼&block ？ 我嘗試了各種各樣的事情，不斷說錯論點。

def start_with_letter_c(pass the return value)
  combinations.select {|word| word.match(/^ca/) }
end

Answer 1

到這里，沒有錯誤：

letters = %w[c s t p b l f g d m  
             y o u i h t r a e l 
             o t l a e m r s n i 
             m a y l p x s e k d]

def combinations(letters)
  combos = letters.combination(4) 
  combos.collect do |letter_set|
    letter_set.join(",").gsub("," ,"")  
  end
end

def start_with_letter_c(combinations)
  combinations.select {|word| word.match(/^ca/) }
end

start_with_letter_c(combinations(letters))
# => ["cael", "caeo", "caet", "cael", "ca ...and so on

Answer 2

我會這樣寫：

letters = %w[c s t p b l f g d m  
             y o u i h t r a e l 
             o t l a e m r s n i 
             m a y l p x s e k d]

def combinations(letters)
  letters.combination(4).map(&:join) 
end

def start_with_letter_c(combinations)
  combinations.select { |word| word.start_with?('ca') }
end

start_with_letter_c(combinations(letters))