integer field 01111

Hello
I created a integer field to postal code and now I have the following problem :
if a user enters the value 01111, field as integer transforms in 1111.
I can edit this field to the value is 01111 or should I create another field text type to this?
Prefer to use the integer field that I have. Have a solution? PERL syntax perhaps?
Thank you.

You can't have leading zeros with an integer field. An integer in PHP does not permit them. The field is typecasted to integer to sanitize it. To have leading zeros you'll need to use a Text field with /^\d+$/ custom regex validation to ensure only digits can be supplied.