Question

I have a stopwatch variable that can get value in the following format:
HH:MM:SS most of the time. 'HH' can go past 24 hours – basically any valid number.

I am not that good with this regex thingy, but was able to write something that is good for most part but fails to validate if the hour is single digit. Ex. below regex pass the time 1:10:09, though it is invalid. valid hour part should be 01.

//var stopWatchTime = '02:10:09'; //Valid
//var stopWatchTime = '00:10:09'; //Valid
//var stopWatchTime = '1234:10:09'; //Valid
//var stopWatchTime = ':10:09'; //Invalid
//var stopWatchTime = 'ax:10:09'; //Invalid
var stopWatchTime = '1:10:09'; //Invalid, should be 01:10:09. 

if(!stopWatchTime .match(/^\d+:\d{2}:\d{2}$/)){
    alert('invalid time- ' + stopWatchTime);
}
else{
    alert('valid time - ' + stopWatchTime);
}

What should I change in the regex to say it should check for any number but should have 2 digits or more in hour part?

Answer 1

/^\d{2,}:\d{2}:\d{2}$/

Change the + to a {2,} to allow it to have two or more characters

If you want to see the things that matches and doesn’t match you can play with it here http://regexr.com?31fu4

EDIT:
Also if you only want to match up to 59 in the hours/minutes part use

^\d{2,}:(?:[0-5]\d):(?:[0-5]\d)$