How to compare strings ignoring the case

I want apple and Apple comparison to be true. Currently

"Apple" == "Apple"  # returns TRUE
"Apple" == "APPLE"  # returns FALSE

You're looking for casecmp. It returns 0 if two strings are equal, case-insensitively.

str1.casecmp(str2) == 0

"Apple".casecmp("APPLE") == 0
#=> true

Alternatively, you can convert both strings to lower case (str.downcase) and compare for equality.

In Ruby 2.4.0 you have: casecmp?(other_str) → true, false, or nil

"abcdef".casecmp?("abcde")     #=> false
"aBcDeF".casecmp?("abcdef")    #=> true
"abcdef".casecmp?("abcdefg")   #=> false
"abcdef".casecmp?("ABCDEF")    #=> true

Here you have more info