ruby - 如果变量被声明为 false，程序如何前进？

Question

程序如何在“bear_moved = false”之后继续？如果 while 语句只运行 while true 程序如何继续运行？还是 while true 与“bear_moved”无关？如果是这样，它也有什么关系？

def bear_room
  puts "There is a bear here."
  puts "The bear has a bunch of honey."
  puts "The fat bear is in front of another door."
  puts "How are you going to move the bear?"
  bear_moved = false

  while true
    print "> "
    choice = $stdin.gets.chomp

    if choice == "take honey"
      dead("The bear looks at you then slaps your face off.")
    elsif choice == "taunt bear" && !bear_moved
      puts "The bear has moved from the door. You can go through it now."
      bear_moved = true
    elsif choice == "taunt bear" && bear_moved
      dead("The bear gets annoyed and chews your leg off.")
    elsif choice == "open door" && bear_moved
      gold_room
    else
      puts "I got no idea what that means."
    end
  end
end

Answer 1

在我看来，您想要如下内容:

def bear_room
  puts "There is a bear here."
  puts "The bear has a bunch of honey."
  puts "The fat bear is in front of another door."
  puts "How are you going to move the bear?"
  bear_moved = false

  until bear_moved
    print "> "
    case gets.chomp
    when "take honey"
      dead("The bear looks at you then slaps your face off.")
    when "taunt bear"
      puts "The bear has moved from the door. You can go through it now."
      bear_moved = true
    when "open door"
      gold_room
    else
      puts "I have no idea what that means."
    end  
  end
  puts "I'm outta' here!"  
end

def dead(str) puts(str) end
def gold_room; puts "So this is the famous gold room. Nice."; end

需要考虑的几点:

• 因为您有 while true，所以您需要一个 break 语句来退出循环。或者，您可以像我一样使用 until bear_moved。如果你想使用 while true(或者更惯用的，loop do)，只需将 until bear_moved 替换为 break .我以不同的方式编写它只是为了向您展示可用的选择。

• 你不需要 when "taunt bear" 下的 if bear_moved...else...end，因为 bear_moved 在该点始终为 false。

• 没有方法或局部变量 dead 或 gold_room，因此您需要对此做些事情。我已经为它们添加了方法。

• 我使用了 case 语句而不是所有的 if-elsif 语句，因为它更易于阅读。此外，您会发现在使用 case 语句时不需要变量 choice。我还只包含了 choice 的结果，在 if-then-else 中为两个 case 结果留下了次要选择.

(我最初有 while bear_moved == false。我在阅读@SteveTurczyn 的回答后将其更改为 until bear_moved。谢谢，Steve。)