如何显示方法参数中的 nil？

Question

这是我第一次post来这里，我是一个超级初学者，我想解决一个练习。

好吧，我想知道如何显示方法参数中的 nil。这是我试过的代码，但是预期的结果不符合我的期望，你能帮我吗？谢谢。

def who_is_bigger(a, b, c)
  max_number = 84
  the_nil = c
  if max_number == a
    puts "a is bigger"
  elsif max_number == b
    puts "b is bigger"
  elsif max_number == c
    puts "c is bigger"
  elsif the_nil == nil
    puts "nil detected"
  else
    puts "nil detected"
  end
end
  
puts who_is_bigger(84, 42, nil)
puts who_is_bigger(nil, 42, 21)
puts who_is_bigger(84, 42, 21)
puts who_is_bigger(42, 84, 21)
puts who_is_bigger(42, 21, 84)

还有我的终端return这个；

a is bigger
nil detected
a is bigger
b is bigger
c is bigger

但我想要这个；

nil detected
nil detected
a is bigger
b is bigger
c is bigger

Answer 1

您需要在其他条件之前进行 nil 开始检查。

def who_is_bigger(a, b, c)
  if [a, b, c].include?(nil)
    puts "nil detected"
    return
  end
  max_number = 84
  if max_number == a
    puts "a is bigger"
  elsif max_number == b
    puts "b is bigger"
  elsif max_number == c
    puts "c is bigger"
  else
    puts "nil detected" # this should really be max_number not found
  end
end

如何显示方法参数中的 nil？

how to display a nil which is in the arguments of a method?

ruby

variables

methods

null

arguments