My test string for the following:
testing='12345,abc,123,54321,ab15234,123456,52341';
If I understand your question, you'd want ["12345", "54321", "15234", "52341"].
If JS engines supported regexp lookbehinds, you could do:
testing.match(/(?<!\d)\d{5}(?!\d)/g)
Since it doesn't currently, you could:
testing.match(/(?:^|\D)(\d{5})(?!\d)/g)
and remove the leading non-digit from appropriate results, or:
pentadigit=/(?:^|\D)(\d{5})(?!\d)/g;
result = [];
while (( match = pentadigit.exec(testing) )) {
result.push(match[1]);
}
Note that for IE, it seems you need to use a RegExp stored in a variable rather than a literal regexp in the while loop, otherwise you'll get an infinite loop.