Check if string is a single emoji

Question

I am trying to check if string is only '' and not '' or doesn't contain more than 1 emoji.

My current code:

await msg.edit('Testing if it\'s a emoji');

    try {
            await msg.react(given);

            await msg.reactions.removeAll();

            emoji = given;
        } catch (err) {
        await msg.edit(`You did not provide a valid emoji. Please try again.`);

        break;
    }

I don't know if its efficient this way. Could you tell me the best way to detect if string has ONLY one emoji?

I found some stackoverflow questions but most of them allow more than 1 emoji. I want it to detect if it has only 1 emoji.

Answer 1

function isOnlyOneEmoji(emoji) {
  const EmojiPattern = /^(?:\uD83D(?:\uDD73\uFE0F?|\uDC41(?:(?:\uFE0F(?:\u200D\uD83D\uDDE8\uFE0F?)?|\u200D\uD83D\uDDE8\uFE0F?))?|[\uDDE8\uDDEF]\uFE0F?|\uDC4B(?:\uD83C[\uDFFB-\uDFFF])?|\uDD90(?:(?:\uD83C[\uDFFB-\uDFFF]|\uFE0F))?|[\uDD96\uDC4C\uDC48\uDC49\uDC46\uDD95\uDC47\uDC4D\uDC4E\uDC4A\uDC4F\uDE4C\uDC50\uDE4F\uDC85\uDCAA\uDC42\uDC43\uDC76\uDC66\uDC67](?:\uD83C[\uDFFB-\uDFFF])?|\uDC71(?:(?:\uD83C(?:[\uDFFB-\uDFFF](?:\u200D(?:[\u2640\u2642]\uFE0F?))?)|\u200D(?:[\u2640\u2642]\uFE0F?)))?|\uDC68(?:(?:\uD83C(?:\uDFFB(?:\u200D(?:\uD83E(?:\uDD1D\u200D\uD83D\uDC68\uD83C[\uDFFC-\uDFFF]|[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD])|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92]|\u2708\uFE0F?))?|\uDFFC(?:\u200D(?:\uD83E(?:\uDD1D\u200D\uD83D\uDC68\uD83C[\uDFFB\uDFFD-\uDFFF]|[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD])|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92]|\u2708\uFE0F?))?|\uDFFD(?:\u200D(?:\uD83E(?:\uDD1D\u200D\uD83D\uDC68\uD83C[\uDFFB\uDFFC\uDFFE\uDFFF]|[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD])|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92]|\u2708\uFE0F?))?|\uDFFE(?:\u200D(?:\uD83E(?:\uDD1D\u200D\uD83D\uDC68\uD83C[\uDFFB-\uDFFD\uDFFF]|[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD])|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92]|\u2708\uFE0F?))?|\uDFFF(?:\u200D(?:\uD83E(?:\uDD1D\u200D\uD83D\uDC68\uD83C[\uDFFB-\uDFFE]|[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD])|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92]|\u2708\uFE0F?))?)|\u200D(?:\uD83E[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD]|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D(?:\uDC69\u200D\uD83D(?:\uDC66(?:\u200D\uD83D\uDC66)?|\uDC67(?:\u200D\uD83D[\uDC66\uDC67])?)|\uDC68\u200D\uD83D(?:\uDC66(?:\u200D\uD83D\uDC66)?|\uDC67(?:\u200D\uD83D[\uDC66\uDC67])?)|\uDC66(?:\u200D\uD83D\uDC66)?|\uDC67(?:\u200D\uD83D[\uDC66\uDC67])?|[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92])|\u2708\uFE0F?|\u2764(?:\uFE0F\u200D\uD83D(?:\uDC8B\u200D\uD83D\uDC68|\uDC68)|\u200D\uD83D(?:\uDC8B\u200D\uD83D\uDC68|\uDC68)))))?|\uDC69(?:(?:\uD83C(?:\uDFFB(?:\u200D(?:\uD83E(?:\uDD1D\u200D\uD83D(?:\uDC69\uD83C[\uDFFC-\uDFFF]|\uDC68\uD83C[\uDFFC-\uDFFF])|[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD])|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92]|\u2708\uFE0F?))?|\uDFFC(?:\u200D(?:\uD83E(?:\uDD1D\u200D\uD83D(?:\uDC69\uD83C[\uDFFB\uDFFD-\uDFFF]|\uDC68\uD83C[\uDFFB\uDFFD-\uDFFF])|[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD])|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92]|\u2708\uFE0F?))?|\uDFFD(?:\u200D(?:\uD83E(?:\uDD1D\u200D\uD83D(?:\uDC69\uD83C[\uDFFB\uDFFC\uDFFE\uDFFF]|\uDC68\uD83C[\uDFFB\uDFFC\uDFFE\uDFFF])|[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD])|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92]|\u2708\uFE0F?))?|\uDFFE(?:\u200D(?:\uD83E(?:\uDD1D\u200D\uD83D(?:\uDC69\uD83C[\uDFFB-\uDFFD\uDFFF]|\uDC68\uD83C[\uDFFB-\uDFFD\uDFFF])|[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD])|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92]|\u2708\uFE0F?))?|\uDFFF(?:\u200D(?:\uD83E(?:\uDD1D\u200D\uD83D(?:\uDC69\uD83C[\uDFFB-\uDFFE]|\uDC68\uD83C[\uDFFB-\uDFFE])|[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD])|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92]|\u2708\uFE0F?))?)|\u200D(?:\uD83E[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD]|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D(?:\uDC69\u200D\uD83D(?:\uDC66(?:\u200D\uD83D\uDC66)?|\uDC67(?:\u200D\uD83D[\uDC66\uDC67])?)|\uDC66(?:\u200D\uD83D\uDC66)?|\uDC67(?:\u200D\uD83D[\uDC66\uDC67])?|[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92])|\u2708\uFE0F?|\u2764(?:\uFE0F\u200D\uD83D(?:\uDC8B\u200D\uD83D[\uDC68\uDC69]|[\uDC68\uDC69])|\u200D\uD83D(?:\uDC8B\u200D\uD83D[\uDC68\uDC69]|[\uDC68\uDC69])))))?|[\uDC74\uDC75](?:\uD83C[\uDFFB-\uDFFF])?|[\uDE4D\uDE4E\uDE45\uDE46\uDC81\uDE4B\uDE47\uDC6E](?:(?:\uD83C(?:[\uDFFB-\uDFFF](?:\u200D(?:[\u2642\u2640]\uFE0F?))?)|\u200D(?:[\u2642\u2640]\uFE0F?)))?|\uDD75(?:(?:\uFE0F(?:\u200D(?:[\u2642\u2640]\uFE0F?))?|\uD83C(?:[\uDFFB-\uDFFF](?:\u200D(?:[\u2642\u2640]\uFE0F?))?)|\u200D(?:[\u2642\u2640]\uFE0F?)))?|[\uDC82\uDC77](?:(?:\uD83C(?:[\uDFFB-\uDFFF](?:\u200D(?:[\u2642\u2640]\uFE0F?))?)|\u200D(?:[\u2642\u2640]\uFE0F?)))?|\uDC78(?:\uD83C[\uDFFB-\uDFFF])?|\uDC73(?:(?:\uD83C(?:[\uDFFB-\uDFFF](?:\u200D(?:[\u2642\u2640]\uFE0F?))?)|\u200D(?:[\u2642\u2640]\uFE0F?)))?|[\uDC72\uDC70\uDC7C](?:\uD83C[\uDFFB-\uDFFF])?|[\uDC86\uDC87\uDEB6](?:(?:\uD83C(?:[\uDFFB-\uDFFF](?:\u200D(?:[\u2642\u2640]\uFE0F?))?)|\u200D(?:[\u2642\u2640]\uFE0F?)))?|[\uDC83\uDD7A](?:\uD83C[\uDFFB-\uDFFF])?|\uDD74(?:(?:\uD83C[\uDFFB-\uDFFF]|\uFE0F))?|\uDC6F(?:\u200D(?:[\u2642\u2640]\uFE0F?))?|[\uDEA3\uDEB4\uDEB5](?:(?:\uD83C(?:[\uDFFB-\uDFFF](?:\u200D(?:[\u2642\u2640]\uFE0F?))?)|\u200D(?:[\u2642\u2640]\uFE0F?)))?|[\uDEC0\uDECC\uDC6D\uDC6B\uDC6C](?:\uD83C[\uDFFB-\uDFFF])?|\uDDE3\uFE0F?|\uDC15(?:\u200D\uD83E\uDDBA)?|[\uDC3F\uDD4A\uDD77\uDD78\uDDFA\uDEE3\uDEE4\uDEE2\uDEF3\uDEE5\uDEE9\uDEF0\uDECE\uDD70\uDD79\uDDBC\uDD76\uDECD\uDDA5\uDDA8\uDDB1\uDDB2\uDCFD\uDD6F\uDDDE\uDDF3\uDD8B\uDD8A\uDD8C\uDD8D\uDDC2\uDDD2\uDDD3\uDD87\uDDC3\uDDC4\uDDD1\uDDDD\uDEE0\uDDE1\uDEE1\uDDDC\uDECF\uDECB\uDD49]\uFE0F?|[\uDE00\uDE03\uDE04\uDE01\uDE06\uDE05\uDE02\uDE42\uDE43\uDE09\uDE0A\uDE07\uDE0D\uDE18\uDE17\uDE1A\uDE19\uDE0B\uDE1B-\uDE1D\uDE10\uDE11\uDE36\uDE0F\uDE12\uDE44\uDE2C\uDE0C\uDE14\uDE2A\uDE34\uDE37\uDE35\uDE0E\uDE15\uDE1F\uDE41\uDE2E\uDE2F\uDE32\uDE33\uDE26-\uDE28\uDE30\uDE25\uDE22\uDE2D\uDE31\uDE16\uDE23\uDE1E\uDE13\uDE29\uDE2B\uDE24\uDE21\uDE20\uDE08\uDC7F\uDC80\uDCA9\uDC79-\uDC7B\uDC7D\uDC7E\uDE3A\uDE38\uDE39\uDE3B-\uDE3D\uDE40\uDE3F\uDE3E\uDE48-\uDE4A\uDC8B\uDC8C\uDC98\uDC9D\uDC96\uDC97\uDC93\uDC9E\uDC95\uDC9F\uDC94\uDC9B\uDC9A\uDC99\uDC9C\uDDA4\uDCAF\uDCA2\uDCA5\uDCAB\uDCA6\uDCA8\uDCA3\uDCAC\uDCAD\uDCA4\uDC40\uDC45\uDC44\uDC8F\uDC91\uDC6A\uDC64\uDC65\uDC63\uDC35\uDC12\uDC36\uDC29\uDC3A\uDC31\uDC08\uDC2F\uDC05\uDC06\uDC34\uDC0E\uDC2E\uDC02-\uDC04\uDC37\uDC16\uDC17\uDC3D\uDC0F\uDC11\uDC10\uDC2A\uDC2B\uDC18\uDC2D\uDC01\uDC00\uDC39\uDC30\uDC07\uDC3B\uDC28\uDC3C\uDC3E\uDC14\uDC13\uDC23-\uDC27\uDC38\uDC0A\uDC22\uDC0D\uDC32\uDC09\uDC33\uDC0B\uDC2C\uDC1F-\uDC21\uDC19\uDC1A\uDC0C\uDC1B-\uDC1E\uDC90\uDCAE\uDD2A\uDDFE\uDDFB\uDC92\uDDFC\uDDFD\uDD4C\uDED5\uDD4D\uDD4B\uDC88\uDE82-\uDE8A\uDE9D\uDE9E\uDE8B-\uDE8E\uDE90-\uDE9C\uDEF5\uDEFA\uDEB2\uDEF4\uDEF9\uDE8F\uDEA8\uDEA5\uDEA6\uDED1\uDEA7\uDEF6\uDEA4\uDEA2\uDEEB\uDEEC\uDCBA\uDE81\uDE9F-\uDEA1\uDE80\uDEF8\uDD5B\uDD67\uDD50\uDD5C\uDD51\uDD5D\uDD52\uDD5E\uDD53\uDD5F\uDD54\uDD60\uDD55\uDD61\uDD56\uDD62\uDD57\uDD63\uDD58\uDD64\uDD59\uDD65\uDD5A\uDD66\uDD25\uDCA7\uDEF7\uDD2E\uDC53-\uDC62\uDC51\uDC52\uDCFF\uDC84\uDC8D\uDC8E\uDD07-\uDD0A\uDCE2\uDCE3\uDCEF\uDD14\uDD15\uDCFB\uDCF1\uDCF2\uDCDE-\uDCE0\uDD0B\uDD0C\uDCBB\uDCBD-\uDCC0\uDCFA\uDCF7-\uDCF9\uDCFC\uDD0D\uDD0E\uDCA1\uDD26\uDCD4-\uDCDA\uDCD3\uDCD2\uDCC3\uDCDC\uDCC4\uDCF0\uDCD1\uDD16\uDCB0\uDCB4-\uDCB8\uDCB3\uDCB9\uDCB1\uDCB2\uDCE7-\uDCE9\uDCE4-\uDCE6\uDCEB\uDCEA\uDCEC-\uDCEE\uDCDD\uDCBC\uDCC1\uDCC2\uDCC5-\uDCD0\uDD12\uDD13\uDD0F-\uDD11\uDD28\uDD2B\uDD27\uDD29\uDD17\uDD2C\uDD2D\uDCE1\uDC89\uDC8A\uDEAA\uDEBD\uDEBF\uDEC1\uDED2\uDEAC\uDDFF\uDEAE\uDEB0\uDEB9-\uDEBC\uDEBE\uDEC2-\uDEC5\uDEB8\uDEAB\uDEB3\uDEAD\uDEAF\uDEB1\uDEB7\uDCF5\uDD1E\uDD03\uDD04\uDD19-\uDD1D\uDED0\uDD4E\uDD2F\uDD00-\uDD02\uDD3C\uDD3D\uDD05\uDD06\uDCF6\uDCF3\uDCF4\uDD31\uDCDB\uDD30\uDD1F-\uDD24\uDD34\uDFE0-\uDFE2\uDD35\uDFE3-\uDFE5\uDFE7-\uDFE9\uDFE6\uDFEA\uDFEB\uDD36-\uDD3B\uDCA0\uDD18\uDD33\uDD32\uDEA9])|\uD83E(?:[\uDD1A\uDD0F\uDD1E\uDD1F\uDD18\uDD19\uDD1B\uDD1C\uDD32\uDD33\uDDB5\uDDB6\uDDBB\uDDD2](?:\uD83C[\uDFFB-\uDFFF])?|\uDDD1(?:(?:\uD83C(?:[\uDFFB-\uDFFF](?:\u200D(?:\uD83E(?:\uDD1D\u200D\uD83E\uDDD1\uD83C[\uDFFB-\uDFFF]|[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD])|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92]|\u2708\uFE0F?))?)|\u200D(?:\uD83E(?:\uDD1D\u200D\uD83E\uDDD1|[\uDDB0\uDDB1\uDDB3\uDDB2\uDDAF\uDDBC\uDDBD])|\u2695\uFE0F?|\uD83C[\uDF93\uDFEB\uDF3E\uDF73\uDFED\uDFA4\uDFA8]|\u2696\uFE0F?|\uD83D[\uDD27\uDCBC\uDD2C\uDCBB\uDE80\uDE92]|\u2708\uFE0F?)))?|[\uDDD4\uDDD3](?:\uD83C[\uDFFB-\uDFFF])?|[\uDDCF\uDD26\uDD37](?:(?:\uD83C(?:[\uDFFB-\uDFFF](?:\u200D(?:[\u2642\u2640]\uFE0F?))?)|\u200D(?:[\u2642\u2640]\uFE0F?)))?|[\uDD34\uDDD5\uDD35\uDD30\uDD31\uDD36](?:\uD83C[\uDFFB-\uDFFF])?|[\uDDB8\uDDB9\uDDD9-\uDDDD](?:(?:\uD83C(?:[\uDFFB-\uDFFF](?:\u200D(?:[\u2642\u2640]\uFE0F?))?)|\u200D(?:[\u2642\u2640]\uFE0F?)))?|[\uDDDE\uDDDF](?:\u200D(?:[\u2642\u2640]\uFE0F?))?|[\uDDCD\uDDCE\uDDD6\uDDD7\uDD38](?:(?:\uD83C(?:[\uDFFB-\uDFFF](?:\u200D(?:[\u2642\u2640]\uFE0F?))?)|\u200D(?:[\u2642\u2640]\uFE0F?)))?|\uDD3C(?:\u200D(?:[\u2642\u2640]\uFE0F?))?|[\uDD3D\uDD3E\uDD39\uDDD8](?:(?:\uD83C(?:[\uDFFB-\uDFFF](?:\u200D(?:[\u2642\u2640]\uFE0F?))?)|\u200D(?:[\u2642\u2640]\uFE0F?)))?|[\uDD23\uDD70\uDD29\uDD2A\uDD11\uDD17\uDD2D\uDD2B\uDD14\uDD10\uDD28\uDD25\uDD24\uDD12\uDD15\uDD22\uDD2E\uDD27\uDD75\uDD76\uDD74\uDD2F\uDD20\uDD73\uDD13\uDDD0\uDD7A\uDD71\uDD2C\uDD21\uDD16\uDDE1\uDD0E\uDD0D\uDD1D\uDDBE\uDDBF\uDDE0\uDDB7\uDDB4\uDD3A\uDDB0\uDDB1\uDDB3\uDDB2\uDD8D\uDDA7\uDDAE\uDD8A\uDD9D\uDD81\uDD84\uDD93\uDD8C\uDD99\uDD92\uDD8F\uDD9B\uDD94\uDD87\uDDA5\uDDA6\uDDA8\uDD98\uDDA1\uDD83\uDD85\uDD86\uDDA2\uDD89\uDDA9\uDD9A\uDD9C\uDD8E\uDD95\uDD96\uDD88\uDD8B\uDD97\uDD82\uDD9F\uDDA0\uDD40\uDD6D\uDD5D\uDD65\uD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FC\u25FB\u25AA\u25AB]\uFE0F?|[\u2615\u26EA\u26F2\u26FA\u26FD\u2693\u26F5\u231B\u23F3\u231A\u23F0\u2B50\u26C5\u2614\u26A1\u26C4\u2728\u26BD\u26BE\u26F3\u267F\u26D4\u2648-\u2653\u26CE\u23E9-\u23EC\u2B55\u2705\u274C\u274E\u2795-\u2797\u27B0\u27BF\u2753-\u2755\u2757\u26AB\u26AA\u2B1B\u2B1C\u25FE\u25FD])$/;
  return EmojiPattern.test(emoji) && emoji.length  <=2 ? 'got correct emoji' : 'wrong emoji try again'
}

console.log(isOnlyOneEmoji('☀')); //got correct emoji
console.log(isOnlyOneEmoji('☀⚡️')); //wrong emoji try again 
console.log(isOnlyOneEmoji('test ☀')); //wrong emoji try again 

I saw this function on another post but I changed it to fit your needs. This accepts only one emoji now

Answer 2

For this case, the solution needs to be coming from the world of regular expressions.

I'll use the npm emoji-regex to manipulate the emoji Unicode blocks. https://en.wikipedia.org/wiki/Emoticons_(Unicode_block)

This solution is pretty simple. Basically, I iterable inside message and check if have more than one emoji using the regex from lib emoji-regex.

const emojiRegex = require('emoji-regex/RGI_Emoji.js');

const checkEmojis = {
  emojis: [],
  regex: emojiRegex(),

  getEmojis(text) {
    let match;
    while ((match = this.regex.exec(text))) {
      this.emojis.push(match[0]);
    }
  },

  haveOneEmoji(message) {
    this.getEmojis(message);
    return this.emojis.length === 1 ? true : false;
  },
};

const message = `Hey! It's a emoji message, \u{231A}:`;

if (checkEmojis.haveOneEmoji(message)) {
  console.log('Have only one emoji in this message!');
} else {
  throw new Error(`You did not provide a valid emoji. Please try again.`);
}

Note: You need to create some tests and validators, for example, if an arg message exists before passing for the methods.