Javascript: is there a shorter way to validate a date with regex? I want to allow m/d/yyyy as well as mm/dd/yyyy

Question

My goal is to validate a user-entered date in javascript.

I am basing my code on https://stackoverflow.com/a/6178341/3255963, but that code was designed to only validate mm/dd/yyyy.

if(!/^\d{2}\/\d{2}\/\d{4}$/.test(dateString))
    return false;

I want to also allow users to enter m/d/yyyy (in other words no leading zeros).

It appears the following works but I was wondering if there is a way to do this with regex in one line.

if(
    !/^\d{2}\/\d{2}\/\d{4}$/.test(dateString) && 
    !/^\d{1}\/\d{1}\/\d{4}$/.test(dateString) &&
    !/^\d{1}\/\d{2}\/\d{4}$/.test(dateString) &&
    !/^\d{2}\/\d{1}\/\d{4}$/.test(dateString)
  )
  return false;

PS Another portion of the linked script verifies other aspects of the input, but I'm not modifying that part.

Please don't use a regex. Do you really want to accept `31/31/2014` as a valid date? Use a full date parser. — Matt Ball, Mar 05 '14 at 04:13
No need for regex - split the string on "/", then cast each element to `Number` and check that it's within a valid range. — laurent, Mar 05 '14 at 04:19
Another part of the linked script deals with other aspects of the date. — CarbonandH20, Mar 05 '14 at 04:20

score 0 · Accepted Answer · edited May 23 '17 at 10:31

0

You can specify minimum and the maximum number of characters to be matched, like this

if(!/^\d{1,2}\/\d{1,2}\/\d{4}$/.test(dateString))

Note: As @Matt suggested in the comments, using RegEx to validate date strings, is not a foolproof way.

edited May 23 '17 at 10:31

Community

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answered Mar 05 '14 at 04:13

thefourtheye

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Another part of the linked script validates other aspects. Is that full script not fullproof? – CarbonandH20 Mar 05 '14 at 04:19
@CarbonandH20 If that parses the date string and validates it, then that should be fine. – thefourtheye Mar 05 '14 at 04:20

Javascript: is there a shorter way to validate a date with regex? I want to allow m/d/yyyy as well as mm/dd/yyyy

1 Answers1