Validating Password using Regex

Question

I am working on a Rails 3 application that needs to validate the password based on the following criteria: must be at least 6 characters and include one number and one

Answer 1

Use lookahead assertions:

/^(?=.*[a-zA-Z])(?=.*[0-9]).{6,}$/
  |             |          |
  |             |          |
  |             |          Ensure there are at least 6 characters.
  |             |
  |             Look ahead for an arbitrary string followed by a number.
  |                        
  Look ahead for an arbitrary string followed by a letter.

Technically in this case you don't need the anchors, but it's good habit to use them.