How do I remove emoji from string

Solution 1:

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).

Solution 2:

I am using one based on this script.

 def strip_emoji(text)
    text = text.force_encoding('utf-8').encode
    clean = ""

    # symbols & pics
    regex = /[\u{1f300}-\u{1f5ff}]/
    clean = text.gsub regex, ""

    # enclosed chars 
    regex = /[\u{2500}-\u{2BEF}]/ # I changed this to exclude chinese char
    clean = clean.gsub regex, ""

    # emoticons
    regex = /[\u{1f600}-\u{1f64f}]/
    clean = clean.gsub regex, ""

    #dingbats
    regex = /[\u{2702}-\u{27b0}]/
    clean = clean.gsub regex, ""
  end

Results:

irb> strip_emoji("👽😀☂❤华み원❤")
=> "华み원"

Solution 3:

This regex matches all 845 emoji, taken from Emoji unicode characters for use on the web:

[\u{203C}\u{2049}\u{20E3}\u{2122}\u{2139}\u{2194}-\u{2199}\u{21A9}-\u{21AA}\u{231A}-\u{231B}\u{23E9}-\u{23EC}\u{23F0}\u{23F3}\u{24C2}\u{25AA}-\u{25AB}\u{25B6}\u{25C0}\u{25FB}-\u{25FE}\u{2600}-\u{2601}\u{260E}\u{2611}\u{2614}-\u{2615}\u{261D}\u{263A}\u{2648}-\u{2653}\u{2660}\u{2663}\u{2665}-\u{2666}\u{2668}\u{267B}\u{267F}\u{2693}\u{26A0}-\u{26A1}\u{26AA}-\u{26AB}\u{26BD}-\u{26BE}\u{26C4}-\u{26C5}\u{26CE}\u{26D4}\u{26EA}\u{26F2}-\u{26F3}\u{26F5}\u{26FA}\u{26FD}\u{2702}\u{2705}\u{2708}-\u{270C}\u{270F}\u{2712}\u{2714}\u{2716}\u{2728}\u{2733}-\u{2734}\u{2744}\u{2747}\u{274C}\u{274E}\u{2753}-\u{2755}\u{2757}\u{2764}\u{2795}-\u{2797}\u{27A1}\u{27B0}\u{2934}-\u{2935}\u{2B05}-\u{2B07}\u{2B1B}-\u{2B1C}\u{2B50}\u{2B55}\u{3030}\u{303D}\u{3297}\u{3299}\u{1F004}\u{1F0CF}\u{1F170}-\u{1F171}\u{1F17E}-\u{1F17F}\u{1F18E}\u{1F191}-\u{1F19A}\u{1F1E7}-\u{1F1EC}\u{1F1EE}-\u{1F1F0}\u{1F1F3}\u{1F1F5}\u{1F1F7}-\u{1F1FA}\u{1F201}-\u{1F202}\u{1F21A}\u{1F22F}\u{1F232}-\u{1F23A}\u{1F250}-\u{1F251}\u{1F300}-\u{1F320}\u{1F330}-\u{1F335}\u{1F337}-\u{1F37C}\u{1F380}-\u{1F393}\u{1F3A0}-\u{1F3C4}\u{1F3C6}-\u{1F3CA}\u{1F3E0}-\u{1F3F0}\u{1F400}-\u{1F43E}\u{1F440}\u{1F442}-\u{1F4F7}\u{1F4F9}-\u{1F4FC}\u{1F500}-\u{1F507}\u{1F509}-\u{1F53D}\u{1F550}-\u{1F567}\u{1F5FB}-\u{1F640}\u{1F645}-\u{1F64F}\u{1F680}-\u{1F68A}]

I generated this regex directly from the raw list of Unicode emoji. The algorithm is here: https://github.com/franklsf95/ruby-emoji-regex.

Example usage:

regex = /[\u{203C}\u{2049}\u{20E3}\u{2122}\u{2139}\u{2194}-\u{2199}\u{21A9}-\u{21AA}\u{231A}-\u{231B}\u{23E9}-\u{23EC}\u{23F0}\u{23F3}\u{24C2}\u{25AA}-\u{25AB}\u{25B6}\u{25C0}\u{25FB}-\u{25FE}\u{2600}-\u{2601}\u{260E}\u{2611}\u{2614}-\u{2615}\u{261D}\u{263A}\u{2648}-\u{2653}\u{2660}\u{2663}\u{2665}-\u{2666}\u{2668}\u{267B}\u{267F}\u{2693}\u{26A0}-\u{26A1}\u{26AA}-\u{26AB}\u{26BD}-\u{26BE}\u{26C4}-\u{26C5}\u{26CE}\u{26D4}\u{26EA}\u{26F2}-\u{26F3}\u{26F5}\u{26FA}\u{26FD}\u{2702}\u{2705}\u{2708}-\u{270C}\u{270F}\u{2712}\u{2714}\u{2716}\u{2728}\u{2733}-\u{2734}\u{2744}\u{2747}\u{274C}\u{274E}\u{2753}-\u{2755}\u{2757}\u{2764}\u{2795}-\u{2797}\u{27A1}\u{27B0}\u{2934}-\u{2935}\u{2B05}-\u{2B07}\u{2B1B}-\u{2B1C}\u{2B50}\u{2B55}\u{3030}\u{303D}\u{3297}\u{3299}\u{1F004}\u{1F0CF}\u{1F170}-\u{1F171}\u{1F17E}-\u{1F17F}\u{1F18E}\u{1F191}-\u{1F19A}\u{1F1E7}-\u{1F1EC}\u{1F1EE}-\u{1F1F0}\u{1F1F3}\u{1F1F5}\u{1F1F7}-\u{1F1FA}\u{1F201}-\u{1F202}\u{1F21A}\u{1F22F}\u{1F232}-\u{1F23A}\u{1F250}-\u{1F251}\u{1F300}-\u{1F320}\u{1F330}-\u{1F335}\u{1F337}-\u{1F37C}\u{1F380}-\u{1F393}\u{1F3A0}-\u{1F3C4}\u{1F3C6}-\u{1F3CA}\u{1F3E0}-\u{1F3F0}\u{1F400}-\u{1F43E}\u{1F440}\u{1F442}-\u{1F4F7}\u{1F4F9}-\u{1F4FC}\u{1F500}-\u{1F507}\u{1F509}-\u{1F53D}\u{1F550}-\u{1F567}\u{1F5FB}-\u{1F640}\u{1F645}-\u{1F64F}\u{1F680}-\u{1F68A}]/
str = "I am a string with emoji 😍😍😱😱👿👿🐔🌚 and other Unicode characters 比如中文."
str.gsub regex, ''
# "I am a string with emoji  and other Unicode characters 比如中文."

Other Unicode characters, such as Asian characters, are preserved.

EDIT: I udpated the regex to exclude ASCII numbers and symbols. See comments for details.

Solution 4:

Most of the answers in this thread don't remove all emojis correctly. They remove simple emojis like 😀 fine. But they won't fully remove multi code point emojis like 👨‍👩‍👧‍👦 or ☸️, leaving some residual unicode code points behind.

You could use a gem like unicode-emoji to get the latest emoji regexes, but if you find this overkill the following code might be a good enough solution:

text.gsub(/[^[:alnum:][:blank:][:punct:]]/, '').squeeze(' ').strip

This will remove any emoji or weird-unicody-like character that is not a basic alphanum/punct/blank.