blocks|key|654898|text|处理此问题的一种方法是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|654899|def+foo(*args)
++++first_name,+last_name,+age,+sex,+is_plumber+=+*args
++++#+some+code
++++#+error+happens+here
++++logger.error+"Method+has+failed,+here+are+all+method+arguments+#{args.inspect}"++++
end|code-block|syntax|javascript|654900|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

One way to handle this is:

<pre><code>def foo(*args)
 first_name, last_name, age, sex, is_plumber = *args
 # some code
 # error happens here
 logger.error "Method has failed, here are all method arguments #{args.inspect}" 
end
</code></pre>

blocks|key|654980|text|这是一个有趣的问题。也许使用local_variables？但除了使用eval之外，肯定还有其他方法。我正在查找内核doc|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|654981|class+Test
++def+method(first,+last)
++++local_variables.each+do+%7Cvar%7C
++++++puts+eval+var.to_s
++++end
++end
end

Test.new().method("aaa",+1)+#+outputs+"aaa",+1|code-block|syntax|javascript|654982|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/3456908/315306|1|http://ruby-doc.org/core-1.9.3/Kernel.html#M001391^0|E|F|0|1M|3|1|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]|$A|W|B|X|1|Y]]|C|$]]|$1|D|3|E|5|F|7|Z|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|10|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]|Q|$5|L|M|N|C|$O|R]]]]

This is an interesting question. Maybe using <a href="https://stackoverflow.com/a/3456908/315306">local_variables</a>? But there must be a way other than using eval. I'm looking in Kernel <a href="http://ruby-doc.org/core-1.9.3/Kernel.html#M001391" rel="nofollow noreferrer">doc</a>

<pre><code>class Test
 def method(first, last)
 local_variables.each do |var|
 puts eval var.to_s
 end
 end
end

Test.new().method("aaa", 1) # outputs "aaa", 1
</code></pre>

blocks|key|655325|text|这可能会有帮助..。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|655326|++def+foo(x,+y)
++++args(binding)
++end

++def+args(callers_binding)
++++callers_name+=+caller[0][/`.*'/][1..-2]
++++parameters+=+method(callers_name).parameters
++++parameters.map+{+%7C_,+arg_name%7C
++++++callers_binding.local_variable_get(arg_name)
++++}++++
++end|code-block|syntax|javascript|655327|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<h1>This may be helpful...</h1>
<pre><code> def foo(x, y)
 args(binding)
 end

 def args(callers_binding)
 callers_name = caller[0][/`.*'/][1..-2]
 parameters = method(callers_name).parameters
 parameters.map { |_, arg_name|
 callers_binding.local_variable_get(arg_name)
 } 
 end
</code></pre>

blocks|key|655382|text|如果您需要参数作为Hash，并且您不想通过棘手的参数提取来污染方法的主体，请使用以下代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|655383|def+mymethod(firstarg,+kw_arg1:,+kw_arg2:+:default)
++args+=+MethodArguments.(binding)+#+All+arguments+are+in+`args`+hash+now
++...
end|code-block|syntax|javascript|655384|只需将此类添加到您的项目中：|655385|class+MethodArguments
++def+self.call(ext_binding)
++++raise+ArgumentError,+"Binding+expected,+#{ext_binding.class.name}+given"+unless+ext_binding.is_a?(Binding)
++++method_name+=+ext_binding.eval("__method__")
++++ext_binding.receiver.method(method_name).parameters.map+do+%7C_,+name%7C
++++++[name,+ext_binding.local_variable_get(name)]
++++end.to_h
++end
end|655386|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

If you need arguments as a Hash, and you don't want to pollute method's body with tricky extraction of parameters, use this:

<pre><code>def mymethod(firstarg, kw_arg1:, kw_arg2: :default)
 args = MethodArguments.(binding) # All arguments are in `args` hash now
 ...
end
</code></pre>

Just add this class to your project:

<pre><code>class MethodArguments
 def self.call(ext_binding)
 raise ArgumentError, "Binding expected, #{ext_binding.class.name} given" unless ext_binding.is_a?(Binding)
 method_name = ext_binding.eval("__method__")
 ext_binding.receiver.method(method_name).parameters.map do |_, name|
 [name, ext_binding.local_variable_get(name)]
 end.to_h
 end
end
</code></pre>

blocks|key|440842|text|您可以定义一个常量，例如：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|440843|ARGS_TO_HASH+=+"method(__method__).parameters.map+{+%7Carg%7C+arg[1].to_s+}.map+{+%7Carg%7C+{+arg.to_sym+=>+eval(arg)+}+}.reduce+Hash.new,+:merge"|code-block|syntax|javascript|440844|并在您的代码中使用它，如下所示：|440845|args+=+eval(ARGS_TO_HASH)
another_method_that_takes_the_same_arguments(**args)|440846|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

You can define a constant such as:

<pre><code>ARGS_TO_HASH = "method(__method__).parameters.map { |arg| arg[1].to_s }.map { |arg| { arg.to_sym =&gt; eval(arg) } }.reduce Hash.new, :merge"
</code></pre>

And use it in your code like:

<pre><code>args = eval(ARGS_TO_HASH)
another_method_that_takes_the_same_arguments(**args)
</code></pre>

blocks|key|440589|text|在我进一步讨论之前，您向foo传递了太多参数。看起来所有这些参数都是模型上的属性，对吗？你真的应该传递对象本身。话到此结束。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|440590|你可以使用"splat“参数。它将所有内容都放入一个数组中。它看起来是这样的：|440591|def+foo(*bar)
++...
++log.error+"Error+with+arguments+#{bar.joins(',+')}"
end|code-block|syntax|javascript|440592|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Before I go further, you're passing too many arguments into foo. It looks like all of those arguments are attributes on a Model, correct? You should really be passing the object itself. End of speech.

You could use a "splat" argument. It shoves everything into an array. It would look like:

<pre><code>def foo(*bar)
 ...
 log.error "Error with arguments #{bar.joins(', ')}"
end
</code></pre>

blocks|key|655191|text|如果你想改变方法签名，你可以这样做：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|655192|def+foo(*args)
++#+some+code
++#+error+happens+here
++logger.error+"Method+has+failed,+here+are+all+method+arguments+#{args}"++++
end|code-block|syntax|javascript|655193|或者：|655194|def+foo(opts={})
++#+some+code
++#+error+happens+here
++logger.error+"Method+has+failed,+here+are+all+method+arguments+#{opts.values}"++++
end|655195|在这种情况下，内插的args或opts.values将是一个数组，但如果使用逗号，则可以使用join。干杯|offset|length|style|CODE|655196|entityMap^0|0|0|0|0|A|4|F|B|1A|4|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|W|8|@$M|X|N|Y|O|P]|$M|Z|N|10|O|P]|$M|11|N|12|O|P]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|13|8|@]|9|@]|A|$]]]|R|$]]

If you would change the method signature, you can do something like this: 

<pre><code>def foo(*args)
 # some code
 # error happens here
 logger.error "Method has failed, here are all method arguments #{args}" 
end
</code></pre>

Or:

<pre><code>def foo(opts={})
 # some code
 # error happens here
 logger.error "Method has failed, here are all method arguments #{opts.values}" 
end
</code></pre>

In this case, interpolated <code>args</code> or <code>opts.values</code> will be an array, but you can <code>join</code> if on comma. Cheers

blocks|key|655259|text|看起来这个问题想要达到的目的可以用我刚刚发布的宝石https://github.com/ericbeland/exception_details来完成。它将列出本地变量和来自被拯救异常的值(以及实例变量)。可能值得一看...|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|655260|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/ericbeland/exception_details^0|P|1B|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

It seems like what this question is trying to accomplish could be done with a gem I just released, <a href="https://github.com/ericbeland/exception_details" rel="nofollow">https://github.com/ericbeland/exception_details</a>. It will list local variables and vlaues (and instance variables) from rescued exceptions. Might be worth a look...

blocks|key|440984|text|如果函数在某个类中，那么您可以这样做：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|440985|class+Car
++def+drive(speed)
++end
end

car+=+Car.new
method+=+car.method(:drive)

p+method.parameters+#=>+[[:req,+:speed]]+|code-block|syntax|javascript|440986|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

If the function is inside some class then you can do something like this: 

<pre><code>class Car
 def drive(speed)
 end
end

car = Car.new
method = car.method(:drive)

p method.parameters #=&gt; [[:req, :speed]] 
</code></pre>

New to Ruby and ROR and loving it each day, so here is my question since I have not idea how to google it (and I have tried :) )

we have method

<pre><code>def foo(first_name, last_name, age, sex, is_plumber)
 # some code
 # error happens here
 logger.error "Method has failed, here are all method arguments #{SOMETHING}" 
end
</code></pre>

So what I am looking for way to get all arguments passed to method, without listing each one. Since this is Ruby I assume there is a way :) if it was java I would just list them :)

Output would be:

<pre><code>Method has failed, here are all method arguments {"Mario", "Super", 40, true, true}
</code></pre>

Is there a way to access method arguments in Ruby?

我是Ruby和ROR的新手，每天都很喜欢它，所以这是我的问题，因为我不知道如何在google上搜索它(我已经尝试过了:)我们有方法def foo(first_name, last_name, age, sex, is_plumber)    # some code    # error happens here    logger.error "Method has failed, here ar

问有没有办法访问Ruby中的方法参数？
EN

回答 9

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问有没有办法访问Ruby中的方法参数？
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