How do I remove emoji from string
emoji, regex, ruby, unicode
Solution
Karol S already provided a solution, but the reason might not be clear:
`"\u1F600"` is actually `"\u1F60"` followed by `"0"`:
"\u1F60" # => "ὠ"
"\u1F600" # => "ὠ0"
You have to use curly braces for code points above FFFF:
"\u{1F600}" #=> ""
Therefore the character class `[\u1F600-\u1F6FF]` is interpreted as `[\u1F60 0-\u1F6F F]`, i.e. it matches `"\u1F60"`, the range `"0"`..`"\u1F6F"` and `"F"`.
Using curly braces solves the issue:
/[\u{1F600}-\u{1F6FF}]/
This matches (emoji) characters in these unicode blocks:
- U+1F600..U+1F64F Emoticons
- U+1F650..U+1F67F Ornamental Dingbats
- U+1F680..U+1F6FF Transport and Map Symbols
You can also use `unpack`, `pack`, and `between?` to achieve a similar result. This also works for Ruby 1.8.7 which doesn't support Unicode in regular expressions.
s = 'Hi!'
#=> "Hi!\360\237\230\200"
s.unpack('U*').reject{ |e| e.between?(0x1F600, 0x1F6FF) }.pack('U*')
#=> "Hi!"
Regarding your Rubular example – Emoji are single characters:
"".length #=> 1
"".chars #=> [""]
Whereas kaomoji are a combination of multiple characters:
"^_^".length #=> 3
"^_^".chars #=> ["^", "_", "^"]
Matching these is a very different task (and you should ask that in a separate question).
Problem
My problem is to remove emoji from a string, but not CJK (Chinese, Japanese, Korean) characters from a string using regex. I tried to use this regex: ``` REGEX = /[^\u1F600-\u1F6FF\s]/i ``` This regex works fine except it also detects the Chinese, Japanese and Korean character where I need those characters. Any idea how to solve this issue?