Question

I’m cleaning up a few phone number entries in a CSV file using Ruby. Some users have entered unwanted characters and I want to sort through and delete them all (some include: periods, parenthesis, hyphens). While writing my code, I realized I could use the .delete method provided by Ruby, like so:

  def clean_num
   @file.each do |line|
    number = line[3]
    #Would need a .delete for every unwanted character?
    clean_number = number.delete(".")
    puts clean_number
   end
  end

What’s a more efficient way to delete the other characters mentioned above?

Answer 1

You’re looking for regular expressions:

clean_number = number.gsub(/[^\d]/, "")

The first argument to gsub is the pattern to find, the second is what to replace each occurrance with.

This replaces everything that isn’t a digit ([^\d]) with an empty string ("").