javascript - Regex expression validation for numbers -


this regex expression have validate situation below:

correct input:

  1. 12345678,12345678,12345678
  2. *space*12345678 , 12345678 , 12345678 , 12345678
  3. 12345678,12345678,*space*
  4. 12345678
  5. *space*12345678,
  6. 12345678,

result: return true(regex expression working correctly situations above.)

wrong input:

  1. 1234567812345678

result: return true (should false)

for wrong input should returning false , return true. should validate wrong input? 

   var validate_commas = /^(\s*\d{8}\s*[,]?\s*)*$/;

thank you

see ambiguity in description more details on why question ambiguous, , how affects answers get.

i assume spaces (ascii 32) arbitrarily allowed:

  • at start of string
  • at end of string
  • before , after comma.

i assume want disallow horizontal tabs, new lines, carriage returns , other whitespace characters matched \s, , allow space (ascii 32) freely specified.

the bnf grammar above assumptions is:

<digit>  ::= "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" <number> ::= <digit> {8} <space>  ::= " " <token>  ::= <space>* <number> <space>* <list>   ::= <token> ( "," <token> )* [ "," <space>* ]

with grammar above, easy write regex solution:

var regex = /^ *\d{8} *(?:, *\d{8} *)*(?:, *)?$/;

ambiguity in description

rather showing examples of string want match, suggested, should specify grammar input. examples may not cover cases, , answerer assumes "don't care" or make assumptions cases not stated in examples.


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