class String

def mb_chars

information about how to change the default Multibyte behavior see ActiveSupport::Multibyte.
For more information about the methods defined on the Chars proxy see ActiveSupport::Multibyte::Chars. For

object. Interoperability problems can be resolved easily with a +to_s+ call.
String and Char work like expected. The bang! methods change the internal string representation in the Chars
The Chars object tries to be as interchangeable with String objects as possible: sorting and comparing between

== Interoperability and configuration

name.mb_chars.reverse.length # => 12

method chaining on the result of any of these methods.
All the methods on the Chars proxy which normally return a string will return a Chars object. This allows

== Method chaining

=> "LJ"
>> "lj".upcase

NOTE: Ruby 2.4 and later support native Unicode case mappings:

=> "LJ"
>> "lj".mb_chars.upcase.to_s

class. If the proxy class doesn't respond to a certain method, it's forwarded to the encapsulated string.
encapsulates the original string. A Unicode safe version of all the String methods are defined on this proxy
It creates and returns an instance of the ActiveSupport::Multibyte::Chars class which

+mb_chars+ is a multibyte safe proxy for string methods.

== Multibyte proxy 
def mb_chars
  ActiveSupport::Multibyte.proxy_class.new(self)
end