我如何获得Ruby类的名称？

Question

How can I get the class name from an ActiveRecord object?

I have:

result = User.find(1)

I tried:

result.class
# => User(id: integer, name: string ...)
result.to_s
# => #<User:0x3d07cdc>"

I need only the class name, in a string ( User in this case). Is there a method for that?

I know this is pretty basic, but I searched both Rails' and Ruby's docs, and I couldn't find it.

Answer 1

你想在对象的类上调用.name ：

result.class.name

Answer 2

Here's the correct answer, extracted from comments by Daniel Rikowski and pseidemann. I'm tired of having to weed through comments to find the right answer...

If you use Rails (ActiveSupport):

result.class.name.demodulize

If you use POR (plain-ol-Ruby):

result.class.name.split('::').last

Answer 3

result.class.to_s和result.class.name有效。

Answer 4

If you want to get a class name from inside a class method, class.name or self.class.name won't work. These will just output Class , since the class of a class is Class . Instead, you can just use name :

module Foo
  class Bar
    def self.say_name
      puts "I'm a #{name}!"
    end
  end
end

Foo::Bar.say_name

output:

I'm a Foo::Bar!

Answer 5

In my case when I use something like result.class.name I got something like Module1::class_name . But if we only want class_name , use

result.class.table_name.singularize

Answer 6

You can use class method for getting class of any object in ruby.

eg

     array= [] 
     => []
     array.class
     => Array

     hash = {}
     => {}
     hash.class
     => Hash

     string = 'This is String'
     => "This is String"
     string.class
     => String