Javascript regex matching on a time

Question

I want to see if the string I have is in the form of HH:MM:SS.

Here is what I have so far:

d = '00:01:01'
d.match(/\d{2}:\d{2}:\d{2}/)
["00:01:02"]

Is there a way to just get a True/False, instead of an array?

Answer 1

Use .test method of Regexp object.

/\d{2}:\d{2}:\d{2}/.test(d)
// true

Answer 2

Perhaps, you can use regex.test(str) but it's also possible using match because on success, match returns an array which is a truthy value and on failure, match returns null which is a falsy value. Check this to understand truthy and falsy .

So, if you use

if(d.match(/\d{2}:\d{2}:\d{2}/)) {
    // true
}
else {
    // false
}

This will work, check this fiddle as an example and this answer as well (about !! ), I've used !! in my example, so you may have doubts.