ruby​​程序基本設計說明

Question

我想用下面的代碼重寫下面的代碼，但我被卡住了。

def ask question 
good_answer = false 
while (not good_answer) 
    puts question 
    reply = gets.chomp.downcase 

    if (reply == 'yes' or reply =='no') 
     good_answer = true 
     if reply == 'yes' 
      answer = true 
     else 
      answer = false 
     end 
    else 
     puts 'Please answer "yes" or "no"' 
    end 
end 
answer 
end 

替換代碼：

def ask question 
    puts question 
    reply = gets.chomp 
    if (reply == 'yes' or reply == 'no') 
     puts reply.capitalize 
    else 
     puts 'Please enter "yes" or "no"' 
     #jump the code to like 2 (but how?)- use while reply != empty & comment the below lines 
     puts question 
     reply = gets.chomp 
    end 
end 

我要跳轉到程序的主要部分是沒有任何跳轉，跳轉或我可以調用方法，該方法裏面？

Answer 1

def ask question 
puts question 
reply = gets.chomp.downcase 
if (reply == 'yes' or reply == 'no') 
    puts reply.capitalize 
else 
    puts 'Please enter "yes" or "no"' 
    ask question # this does the looping of loop 
end 
end 

謝謝，對不起，我沒有從我的剪貼板上一次複製它做好。

Answer 2

我想跳轉到程序的主要部分是否有任何轉到，跳轉或我可以調用該方法內的方法？

是的，它被稱爲循環，即您在原始代碼中使用的是什麼。爲什麼在這個世界上你想要用goto代替一個循環？沒有意義。

然而它可以被簡化。我不喜歡對「是」或「否」的檢查，但我也沒有時間重新調整程序。

def ask question 
    while true 
    puts(question) 
    reply = gets.chomp.downcase 
    if reply == 'yes' || reply == 'no' 
     return reply == 'yes' 
    else 
     puts('Please answer "yes" or "no"') 
    end 
    end 
end 

Answer 3

即使有goto聲明，你也不應該使用它。這不僅是糟糕的形式，而且由於程序最終難以遵循，所以它會給維護人員帶來各種麻煩。

一個更好的方法是定義適當的結構以您的問題和有效的答案，然後簡單地遍歷這些，收集結果到一個結構，你可以在以後使用：

# Auto-flush output buffer 
STDOUT.sync = true 

questions = [ 
    [ 'Is this a good question?', 'yes', 'no' ], 
    [ 'Is the sky blue?', 'yes', 'no' ], 
    [ 'Do hamsters fly?', 'no', 'yes' ] 
] 

answers_given = [ ] 

questions.each do |question, *answers| 
    print question + ' ' 

    while (true) 
    answer = gets 

    answer.chomp! 

    if (answers.include?(answer)) 
     puts "Thanks!" 

     answers_given << (answer == answers.first) 

     break 
    end 

    puts "You must answer one of #{answers.join(', ')}!" 
    print question + ' ' 
    end 
end 

questions.each_with_index do |(question, *answers), i| 
    puts "#{question} #{answers_given[i]}" 
end 

Answer 4

你可以試一下liek這樣的：

def ask_question 
    puts('Please answer "yes" or "no"') until (reply = gets.chomp.downcase) =~ /^(yes|no)$/ 

    return reply == 'yes' 
end