How can I delete special characters?

Question

I\'m practicing with Ruby and regex to delete certain unwanted characters. For example:

input = input.gsub(/<\\/?[^>]*>/, \'\')

and fo

Answer 1

First of all, I think it might be easier to define what constitutes "correct input" and remove everything else. For example:

input = input.gsub(/[^0-9A-Za-z]/, '')

If that's not what you want (you want to support non-latin alphabets, etc.), then I think you should make a list of the glyphs you want to remove (like ™ or ☻), and remove them one-by-one, since it's hard to distinguish between a Chinese, Arabic, etc. character and a pictograph programmatically.

Finally, you might want to normalize your input by converting to or from HTML escape sequences.

Answer 2

An easier way to do this inspirated by Can Berk Güder answer is:

In order to delete special characters:

input = input.gsub(/\W/, '')

In order to keep word characters:

input = input.scan(/\w/)

At the end input is the same! Try it on : http://rubular.com/

Answer 3

You can match all the characters you want, and then join them together, like this:

original = "aøbæcå"
stripped = original.scan(/[a-zA-Z]/).to_s
puts stripped

which outputs "abc"

Answer 4

If you just wanted ASCII characters, then you can use:

original = "aøbauhrhræoeuacå" 
cleaned = ""
original.each_byte { |x|  cleaned << x unless x > 127   }
cleaned   # => "abauhrhroeuac"

Answer 5

You can use parameterize:

'@!#$%^&*()111'.parameterize
 => "111"