In general, you need to output the user id from the id to the comma. In this code, displays "id50,", you only need "50". How?)

text = 'id50, 4124fdgfgdfg'; if(text.match('id[0-9].*,')){ komy = text.match('id[0-9].*,'); alert(komy); }

    5 answers 5

    Using the regular expression ^id(\d+),.*$ (Captures the number in brackets after id, and before the comma). You can immediately capture the second part ( 4124fdgfgdfg ), with the following expression: /^id(\d+), (.*)$/ .

    Working example:

     str = 'id42, 4124fdgfgdfg'; if (m = str.match(/^id(\d+), (.*)$/)) { console.log(m[1], m[2]) }

    Gives to the console (you can click the "Run code" button to check):

    42 4124fdgfgdfg

    Here is a good description of match in Russian: https://developer.mozilla.org/ru/docs/Web/JavaScript/Reference/Global_Objects/String/match

    Here https://regex101.com/ you can play online with regular expressions and immediately see the result. Here is your example with tests and comments: https://regex101.com/r/nX1rF5/2

    • That's just when a match or exec will have to cut the bikes, otherwise the Cannot read property '1' - Mr. Black
    • @Doofy is likely to need the input string condition anyway, so this is even a plus. Well, as a bonus, you can capture several different substrings at once with different patterns. - Vladimir Gamalyan
    • I do not agree. In my answer, one line and id is either found or not, without unnecessary checks - Mr. Black
    • You read my thoughts straight, you just needed to make a division into ID and the following text) Thank you) - Albert Ushakov

    A bunch of options:
    You can correct the expression itself and will work:

     // (?<=id) - смотрит позитивно назад, но не берёт в результат // (?=,) - смотрит позитивно вперёд, но не берёт в результат // + перед выражением пытается привести результат к Number // // Вернётся либо ["50"], либо null; // массив с одним элементом попытается привести первый элемент // null станет 0 // Используйте эти знания на благо Вашей проверки :) console.info(+/(?<=id)\d*(?=,)/.exec('id50, 4124fdgfgdfg')); // 50

    You can, of course, use the good old groups (you can even do the named ones ):

     // С помощью тернарного оператора проверяем на null // Если null - вернём 0 // Если есть результат - приводим к Number 1 элемент (в 0 - всё совпадение, т. е. id50,) console.info((r = /id(\d*),/.exec('id50, 4124fdgfgdfg')) ? +r[1] : 0); // 50

    It is possible to pervert the type String.prototype.split , where the number is saved with the help of the same groups, but why use a hacksaw for hammering nails?

    • one
      for the first example: "Uncaught SyntaxError: Invalid regular expression: / (? <= id) \\ d * (? =,) /: Invalid group", - Grundy
    • @Grundy, because js does not support this thing. - Qwertiy ♦
    • @Qwertiy, but the question is about js - Grundy
    • @Grundy, but the answer is not mine;) - Qwertiy ♦
    • @Qwertiy, so no complaints about you :-) - Grundy

    When a match or exec to use additional checks, otherwise the error Cannot read property '1' is possible

    split will either find or not ( undefined )

     text = 'id50, 4124fdgfgdfg'; t = text.split(/id(\d+), (.*)/); console.log(t[1], t[2]); 

       text = ' id50, 4124fdgfgdfg'; console.log(text.replace(/id(\d+)\s*,.*|./gi, '$1')) text = ' id50, 4124fdgfgdfg id100,'; console.log(text.replace(/id(\d+)\s*,.*|./gi, '$1')) text = ' id, 4124fdgfgdfg'; console.log(text.replace(/id(\d+)\s*,.*|./gi, '$1'))

        No, but you can (along with id ):

         /id\d[^,]*/