How to compare strings ignoring the case

Question

I want apple and Apple comparison to be true. Currently

\"Apple\" == \"Apple\"  # returns TRUE
\"Apple\" == \"APPLE\"          


        

Answer 1

In case you have to compare UTF-8 strings ignoring case:

>> str1 = "Мария"
=> "Мария"
>> str2 = "мария"
=> "мария"
>> str1.casecmp(str2) == 0
=> false
>> require 'active_support/all'
=> true
>> str1.mb_chars.downcase.to_s.casecmp(str2.mb_chars.downcase.to_s) == 0
=> true

It works this way in Ruby 2.3.1 and earlier versions.

For smaller memory footprint you can cherry pick string/multibyte:

require 'active_support'
require 'active_support/core_ext/string/multibyte'

Edit, Ruby 2.4.0:

>> str1.casecmp(str2) == 0
=> false

So casecmp doesn't work in 2.4.0; However in 2.4.0 one can compare UTF-8 strings manually without active_support gem:

>> str1.downcase == str2.downcase
=> true