ord

Returns the codepoint of the first character of the string, assuming a single-byte character encoding:

"a".ord # => 97
"à".ord # => 224, in ISO-8859-1

This method is defined in Ruby 1.8 for Ruby 1.9 forward compatibility on these character encodings.

ActiveSupport::Multibyte::Chars#ord is forward compatible with Ruby 1.9 on UTF8 strings:

"a".mb_chars.ord # => 97
"à".mb_chars.ord # => 224, in UTF8

Note that the 224 is different in both examples. In ISO-8859-1 “à” is represented as a single byte, 224. In UTF8 it is represented with two bytes, namely 195 and 160, but its Unicode codepoint is 224. If we call ord on the UTF8 string “à” the return value will be 195. That is not an error, because UTF8 is unsupported, the call itself would be bogus.