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Does anyone have a reference for to a javascript reg exp for the date pattern MM / YYYY? I've been researching only to find the usual MM/DD/YYYY, etc.

bntrns
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5 Answers5

6

how about:

This literal here for a regex: /[\d]{2}\/[\d]{4}/

alternatively it looks like you're wanting space between the m and ys so:

/[\d]{2} \/ [\d]{4}/

bluetoft
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  • Depending on the use, you might want to anchor it with `^` and `$` – Ian Jun 27 '13 at 18:45
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    You don't need `[]` if you're only matching `\d`. The question actually has spaces around the `/`. – Paul S. Jun 27 '13 at 18:46
  • It would be as MM/YYYY, without the spaces – bntrns Jun 27 '13 at 18:50
  • Indeed I should have added the ^ to the beginning to ensure an exact match `/^[\d]{2}\/[\d]{4}/` – bluetoft Jun 27 '13 at 18:59
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    @Ben Be careful with this solution. It allows months 13-99. Check out dav's solution so your month is 1-12. – Shaz Jun 27 '13 at 19:03
  • I'm using this with DOJO and had to mash some stuff so the final was ^([0-2][0-9]\/(19|20)[0-9]{2})$... dojo for some reason doesn't like [/d] – bntrns Jun 27 '13 at 19:05
5

(0?[1-9]|1[0-2])\/(\d{4})

This ensures you get a valid month, whether it be two or one digits. I'm assuming you don't want to restrict the year.

http://rubular.com/r/W461W8GyHn

dav
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1

My answer is:

(0[1-9]|1[0-2])/(\d{4}[^0-9])

Example: http://regexr.com?35cl5

AndyDaSilva52
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Simply remove the part of the regex that matches the day (DD). In this similar post, the answer

function parseDate(str) {
  var m = str.match(/^(\d{1,2})-(\d{1,2})-(\d{4})$/);
  return (m) ? new Date(m[3], m[2]-1, m[1]) : null;
}

was given. Just edit the regex slightly to remove one of the 2 decimal matches, and you get the function

  var m = str.match(/^(\d{1,2})\/(\d{4})$/);
Community
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Eric Palace
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You don't need to use regex for this

var date=input.split("/");
var month=parseInt(date[0],10);
var year=parseInt(date[1],10);

if(isNaN(month) || isNaN(year))//invalid string
else //check if month and year is valid

parseInt would evaluate to NaN incase the format is not proper.So,in a way you are validating the string

If you want regex

 ^\d{2}/\d{4}$
Anirudha
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    You didn't answer the question though... – bluetoft Jun 27 '13 at 18:48
  • @Bluetoft it would throw `NaN` in case string is not well formed – Anirudha Jun 27 '13 at 18:50
  • true... but you still didn't provide a regex as the op requested. – bluetoft Jun 27 '13 at 18:55
  • @Anirudh The question was in the form of 'How can I do this with regex?' and you answered in the form of 'Here's a solution that doesn't use regex'. It's not an argument of whether your solution finds a valid month and year, it's an argument of not satisfying the requirements of the question. – Shaz Jun 27 '13 at 18:55
  • @RyanWH still he would have to individually check if month and year is valid by parsing it to int..there is no need of regex – Anirudha Jun 27 '13 at 19:03
  • @Anirudh You can't be sure of that, as you don't know his entire problem. If he was wanting a regex to simply detect if there's a month and a year, he could use dav's solution. dav's solution allows a leading zero on the month and only allows 1-12. No parsing is required. – Shaz Jun 27 '13 at 19:06