14

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

Mr. Demetrius Michael
  • 2,326
  • 5
  • 28
  • 40
  • 3
    Those three characters really getting to you? – Dave Newton Mar 31 '12 at 21:50
  • 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? – Mr. Demetrius Michael Mar 31 '12 at 21:54
  • 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... – Pafjo Mar 31 '12 at 22:02
  • `delete` doesn't take a regex. You can always create a String method like `gdel` or something that does what you want. – Dave Newton Mar 31 '12 at 22:03
  • 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. – sawa Mar 31 '12 at 23:21
  • 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. – Mr. Demetrius Michael Apr 02 '12 at 21:18

4 Answers4

5

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

string[/[^\/]*$/]
DigitalRoss
  • 143,651
  • 25
  • 248
  • 329
5

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.

joelparkerhenderson
  • 34,808
  • 19
  • 98
  • 119
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 :)

Castilho
  • 3,147
  • 16
  • 15
2

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 :)

RonY
  • 21
  • 2
  • I haven't been able to use delete with POSIX bracket expressions like `[[:word:]]`. Is it possible? https://ruby-doc.org/core-3.1.1/Regexp.html#class-Regexp-label-Character+Classes – chemturion Mar 11 '22 at 16:08