ruby – 如何写出复杂的条件

当您具有简单的条件和可能复杂的主体时,条件结构很容易编写：

if simple_condition_expressed_in_one_liner
  complicated_body_that_may_be_long
  complicated_body_that_may_be_long
  complicated_body_that_may_be_long
end

但有时,你有一个复杂的条件和一个像这样的简单的身体：

if condition1 and
condition2 and
condition3 and
some_more_complicated_condition_that_cannot_be_written_on_a_single_line and
still_some_more_complicated_condition_that_cannot_be_written_on_a_single_line
  simple_body
end

在这种情况下,有没有一个好的方法来写它？

解决方法

我总是尝试重构为较小的描述性方法.

使用您的示例,而不是：

until (print "Username : "; gets.chomp == "user") and
      (print "Password : "; gets.chomp == "pa$$word")
  puts "Error,incorrect details"
end

我会用：

def correct_user
  print "Username : "
  gets.chomp == "user"
end

def correct_password
  print "Password : "
  gets.chomp == "pa$$word"
end

until correct_user and correct_password
  puts "Error,incorrect details"
end