从外部方法调用 ruby 循环的 next [英] call next on ruby loop from external method
问题描述
在 Ruby 中很容易告诉循环转到下一项
in Ruby it's easy to tell loop to go to next item
(1..10).each do |a|
next if a.even?
puts a
end
结果 =>
1
3
5
7
9
但是如果我需要从循环外部调用 next 怎么办(例如:方法)
but what if I need to call next from outside of the loop (e.g.: method)
def my_complex_method(item)
next if item.even? # this will obviously fail
end
(1..10).each do |a|
my_complex_method(a)
puts a
end
我找到并有效的唯一解决方案是使用 throw
&catch
就像 SO 问题 如何打破外循环红宝石?
only solution I found and works is to use throw
& catch
like in SO question How to break outer cycle in Ruby?
def my_complex_method(item)
throw(:skip) if item.even?
end
(1..10).each do |a|
catch(:skip) do
my_complex_method(a)
puts a
end
end
我的问题是:有人有更漂亮的解决方案来做到这一点吗??还是 throw/catch
唯一的方法??
My question is: anyone got any more niftier solution to do this ?? or is throw/catch
only way to do this ??
还有什么如果我想调用 my_complex_method
不仅作为该循环的一部分(=> 不要抛出 :skip),我能以某种方式告诉我的方法它是从循环中调用的吗?
Also what If I want to call my_complex_method
not only as a part of that loop (=> don't throw :skip) , can I somehow tell my method it's called from a loop ?
推荐答案
您的复杂方法可以返回一个布尔值,然后您可以像这样在循环中进行比较:
You complex method could return a boolean, and then you compare on your loop like this:
def my_complex_method(item)
true if item.even?
end
(1..10).each do |a|
next if my_complex_method(a)
puts a
end
一种简单的方法,但与 try catch 不同.
A simple approach, but different from the try catch one.
更新
由于 item.even?
已经返回一个布尔值,你不需要 true if item.even?
部分,你可以这样做:>
As item.even?
already return a boolean value, you don't need the true if item.even?
part, you can do as follow:
def my_complex_method(item)
item.even?
end
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