通过包含字段名称的字符串变量引用模型字段？(Refer to model field by string variable that contains the name of the field?)

通过包含字段名称的字符串变量引用模型字段？(Refer to model field by string variable that contains the name of the field?)

我无法弄清楚如何用谷歌搜索这个词 - 请原谅。 如果我有一个像这样的模型：

c = Color.all

我可以说：

c.Color[0].color_name

因此，如果我有一个包含该模型中字段名称的变量，如：

b = 'color_name'

我怎么能这样说（“c.color_name”）使用带有字段名称的字符串：

c[0].b

或者，我的意思是告诉Ruby / Rails使用vaiable的内容作为字段名称：

c[0].[the string value of b]

我已经摸索着尝试我能想到的一切，但是我无法弄清楚这个的语法。

谢谢！

Rails 2.3.5 / Ruby 1.8.7

I can't figure out how to word this for a google search - pardon. If I have a model like:

c = Color.all

I could say:

c.Color[0].color_name

So if I then have a variable that contains the name of a field in that model like:

b = 'color_name'

How could I say ("c.color_name") like this using the string with the field name:

c[0].b

Or, I mean tell Ruby/Rails to use the contents of the vaiable as the field name:

c[0].[the string value of b]

I've fumbled around trying everything I can think of but the syntax for this I can't figure out.

Thanks!

Rails 2.3.5 / Ruby 1.8.7

最满意答案

如果b是Color的实例变量或方法，请使用Object的send方法

c = Color.all b = 'color_name' c[0].send(b.to_sym)

If b is an instance variable or method of a Color, use the send method from Object

c = Color.all b = 'color_name' c[0].send(b.to_sym)