Regular Expression to ensure between 7 and 16 characters with at least 1 numeric character?

Question

I am using the LiveValidation library found at www.livevalidation.com to handle client-side validation. One of the functions is to test for a regular expression. The example they provide on the site is to check if the phrase 'live' is within the a sentence. The code for that is:

var f2 = new LiveValidation('f2');
f2.add( Validate.Format, { pattern: /live/i } );

What would the regular expression be if I wanted to ensure that what was entered was between 7 and 16 characters and containted at least 1 numeric?

Answer 1

You could use a lookahead assertion:

/^(?=.{7,16}$)\D*\d/
/^(?=\D*\d).{7,16}$/

Answer 2

This is a situation where, imo, 2 is better than one

var f2 = new LiveValidation('f2');
f13.add( Validate.Length, { minimum: 7, maximum: 16 } );
f2.add( Validate.Format, { pattern: /\d/ } );