which is better?

[Ruby Newbee]

Hi,

I want to delete the numbers in a string, for example,

x="abcd1234"

I have two ways:

x.gsub! /\d+/,""

x[/\d+/]=""


Which one is better?
I personally prefer the second one.

Thanks.

 

[botp]

x.gsub! /\d+/,""

x[/\d+/]=""

try also String#delete

 

[Florian Gilcher]

Hi,

I want to delete the numbers in a string, for example,

x="abcd1234"

I have two ways:

x.gsub! /\d+/,""

x[/\d+/]=""


Which one is better?
I personally prefer the second one.

The first. It doesn't fail if the string contains no numbers:

x ="abcd"

x[/\d+/]=""
IndexError: regexp not matched
from (irb):10:in `[]='
from (irb):10
from /usr/local/bin/irb19:12:in `<main>'

Regards,
Florian

 

[Robert Klemme]

Hi,

I want to delete the numbers in a string, for example,

x=3D"abcd1234"

I have two ways:

x.gsub! /\d+/,""

x[/\d+/]=3D""


Which one is better?
I personally prefer the second one.

The first. It doesn't fail if the string contains no numbers:

x =3D"abcd"

x[/\d+/]=3D""
IndexError: regexp not matched
=A0 =A0 =A0 =A0from (irb):10:in `[]=3D'
=A0 =A0 =A0 =A0from (irb):10
=A0 =A0 =A0 =A0from /usr/local/bin/irb19:12:in `<main>'

And then there's also

irb(main):001:0> "123ab".tr "0-9", ""
=3D> "ab"
irb(main):002:0> "123ab".tr! "0-9", ""
=3D> "ab"

Cheers

robert

--=20
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

 

[Wybo Dekker]

And then there's also

irb(main):001:0> "123ab".tr "0-9", ""
=> "ab"
irb(main):002:0> "123ab".tr! "0-9", ""
=> "ab"

But why no parentheses?:
irb(irb):13: warning: ambiguous first argument; put parentheses or even spaces
=> "abcd"=> "ab"

what is the ambiguity in the first case, and why is there no warning in the
second case?

 

[Robert Klemme]

But why no parentheses?:
irb
(irb):13: warning: ambiguous first argument; put parentheses or even spaces
=> "abcd"
=> "ab"

what is the ambiguity in the first case, and why is there no warning in the
second case?

Seems to be related to the regexp:

10:56:19 $ ruby19 -wce 'o.gsub! /\d/, ""'
-e:1: warning: ambiguous first argument; put parentheses or even spaces
Syntax OK
10:56:42 $ ruby19 -wce 'o.gsub! "d", ""'
Syntax OK
10:56:50 $ ruby19 -wce 'o.gsub!(/\d/, "")'
Syntax OK
10:57:01 $

Why? No idea.

Cheers

robert

 

[Bertram Scharpf]

Hi,

Am Donnerstag, 10. Dez 2009, 18:58:04 +0900 schrieb Robert Klemme:

Seems to be related to the regexp:

10:56:19 $ ruby19 -wce 'o.gsub! /\d/, ""'
-e:1: warning: ambiguous first argument; put parentheses or even spaces
Syntax OK
10:56:42 $ ruby19 -wce 'o.gsub! "d", ""'
Syntax OK
10:56:50 $ ruby19 -wce 'o.gsub!(/\d/, "")'
Syntax OK
10:57:01 $

Why? No idea.

The slash could also be a division operator. Say:

$ ruby -wce 'o.gsub! %r/\d/, ""'
$ ruby -wce 'o.gsub! %r{\d}, ""'

Bertram