Number Validation with Regex in Ruby

https://medium.com/launch-school/number-validation-with-regex-ruby-393954e46797

def number?(obj)
  obj = obj.to_s unless obj.is_a? String
  /\A[+-]?\d+(\.[\d]+)?\z/.match(obj)
end


/\A[+-]?\d+(\.\d+)?\z/
/         start of the regex
\A        start of the string to be matched
[+-]?     zero or one of '+' or'-'
\d+       one or more of digit
(\.\d+)?  zero or one of 'one dot and 'one or more of digit'' 
\z        end of the string to be matched
/         end of the regex