I'm trying to create a regex for correct username validation in Ruby on Rails but for some reason I am doing something incorrect where all username inputs are invalid. I am allowing for upper-case characters, lower-case characters, numbers, and underscores.
Ruby on Rails name validation regex code:
validates :name, :format => {:with => /\A[A-Za-z\d_]\z/}
What am I doing wrong?
Thanks
validates :name, :format => {:with => /^[A-Za-z0-9\_]+$/}
Nice page to test regular expressions in ruby: http://rubular.com/
\A\z with ^$ see: guides.rubyonrails.org/security.html#regular-expressions# \A[A-Za-z\d_]\z
#
# Options: ^ and $ match at line breaks
#
# Assert position at the beginning of the string «\A»
# Match a single character present in the list below «[A-Za-z\d_]»
# A character in the range between “A” and “Z” «A-Z»
# A character in the range between “a” and “z” «a-z»
# A single digit 0..9 «\d»
# The character “_” «_»
# Assert position at the very end of the string «\z»
This is your expression. Do you really want to match a single character?
I believe that :
/^\w+$/
this is what you are looking for. \w is a shorthand character class for what you have written. The above regex will match a string which consists only of A-Za-Z0-9_
