Is there a Regex Delete in Ruby?

Question

All of my string delete's with regex use gsub, is there a shorter way? string.gsub(/\A.*\//,'')

Sanitarium

Those three characters really getting to you? – Quinton

lol seem to be doing a lot of string deletes. But doing it via gsub, seems like I'm doing it wrong. It should be done via string.delete, no? – Sanitarium

string.delete only takes what characters to delete, no regexp. string.slice! can be used to remove part of a string based on a regexp but is's longer then gsub... – Tranship

delete doesn't take a regex. You can always create a String method like gdel or something that does what you want. – Quinton

Do you need to do that in one position per string or multiple positions? Your expression has gsub (instead of sub) which means you are expecting multiple matches, but you also have \A in the regex, which means you are expecting only one match. Depending on that, solutions become different. – Floodgate

Multiple positions, sorry copied one of the gsubs as a poor example. I'm just surprised delete doesn't incorporate regex. Seems like it'll be more consistent with Ruby's ideology if it did. – Sanitarium

Answer 1

One way is to add your own short methods:

class String

  def del(regexp)
    gsub(regexp,'')
  end

  def del!(regexp)
    gsub!(regexp,'')
  end

end

Typically this code would go in a lib/ directory, for example lib/string-extensions.rb

Heads up that some programmers really dislike this because it's monkey-patching. I personally like it for projects because it makes code easier to understand - once I have the "del" method, I can quickly see that calls to it are just deleting the regexp.

Rheims

Answer 2

You could instead specify the part of the string you want to keep . . .

string[/[^\/]*$/]

Stinkhorn

Answer 3

I don't think so.

String::delete deletes characters, and does not match regex, it's a completely different approach.

The only way I can think of making that line of yours "shorter" is to use string.gsub!(/\A.*\//,'') (notice the bang there).

That's the way to go, I think :)

Periodate

Answer 4

You can use String::delete by specifying a regex in the argument.

Say you want to delete all non AlphaNumeric from a string...

a="Test String with &(*ille#*)gal char!@#acters ^lorem % ipsum $"

a.delete!('^a-zA-Z0-9 .')

Ofcourse be careful to include Whitespace and DOT

Above code will yield the following output

"Test String with illegal characters lorem  ipsum "

This is just an example.

Hope this helps :)

Canal

I haven't been able to use delete with POSIX bracket expressions like [[:word:]]. Is it possible? ruby-doc.org/core-3.1.1/… – Pentathlon