How can I use a regular expression to validate month input?

Question

I am setting up this example Perl snippet to validate for months in a date:

Some scenarios I want to accept are:

MM M

#!/usr/bin/perl
use str         


        

Answer 1

"^(1[012]|0?[1-9])$" would be better because regular expression is assessed first one first. Let's say you want to match '12' and you write "^(0?[1-9]|1[012])$", then '1' will be picked because 0?[1-9] is taken first.

Answer 2

If you really like to use regex, you need to put ^ and $, like

"^(0?[1-9]|1[012])$"

it will not match 13, 14 ....

Answer 3

[^d>12|d<0] OR ^[d>12|d<0]

Answer 4

To give you hint - month number "120" also matches in your version :-)

Change:

my $month = "(0[1-9]|1[012])";

to

my $month = /^(0[1-9]|1[012])$/;

and then play more with it

Answer 5

(0[1-9]|1[012])

the parens are so you can use this inside another block, for example if matching for an entire yyyy-MM-dd date format

source: http://www.regular-expressions.info/dates.html

Answer 6

To test month / year :

^(0?[1-9]|1[012])\/([2-9][0-9)]{3})$