regular expression php how to add empty string in it

Question

i have this regular expression in php:

if (!preg_match('/^([1-9]|1[012])(,([1-9]|1[012]))*$/', $value))

and i want this condition to not run when the $value is just an empty string '' but it runs on empty string please help

Ahmed's advice is equivalent to `if ($value)`. Both are "loose comparisons". https://3v4l.org/TfY3i — mickmackusa, Jul 02 '20 at 00:04
Alternatively, you could just as `(` and `)?` to make the expression between `^` and `$` optional. [`/^([1-9]|1[012](,([1-9]|1[012]))*)?$/`](https://3v4l.org/TE9bX) but I prefer simply doing `if ($value)`. — mickmackusa, Jul 02 '20 at 00:10

score 0 · Accepted Answer · answered Jul 01 '20 at 22:27

0

Check for the empty string separately.

if ($value != '' && !preg_match('/^([1-9]|1[012])(,([1-9]|1[012]))*$/', $value))

answered Jul 01 '20 at 22:27

Barmar

yeah i tried but somehow i messed up && and wrote || instead of &&. thank you that will work. – Muhammad Kashif Jul 01 '20 at 22:35

1 Answers1