Question

I’ve been using this regular expression for validating UK postcodes in my contact forms and it works fine:

/^([a-zA-Z]){1}([0-9][0-9]|[0-9]|[a-zA-Z][0-9][a-zA-Z]|[a-zA-Z][0-9][0-9]|[a-zA-Z][0-9]){1}([ ])([0-9][a-zA-z][a-zA-z]){1}$/

however I now need it to be modified to validate with or without a space e.g. GL50 1HX or GL501HX

Is there an easy solution to this?

Answer 1

To specify an optional space in a regular expression, put a question mark after it.

Example:

^[A-Z]{2}\d{2} ?\d[A-Z]{2}$

The question mark is the short form for the {0,1} qualifier, i.e. zero or one times:

^[A-Z]{2}\d{2} {0,1}\d[A-Z]{2}$