.include? for string

ruby-talk
1

Hi,

I have an array a

=> [["abc", "def", "ghi|ghi|kl"], ["jkl", "mno", "ghi|pqr"], ["stu",
"vwx", "yz|abc"]]

Some strings contain the pipe character.

I want to delete all the arrows that do NOT contain a certain string.

I tried this:

a.delete_if { |x| !x.include? "ghi|ghi" }

=> []

Of course, the array I need would be
=> [["abc", "def", "ghi|ghi|kl"]]

I couldn't figure out a work around. Any wildcards available for string
checking in Ruby? Any ideas?
Thanks.

Cheers,
Chris

···

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Posted via http://www.ruby-forum.com/.

2

Chris Chris wrote:

Hi,

I have an array a

=> [["abc", "def", "ghi|ghi|kl"], ["jkl", "mno", "ghi|pqr"], ["stu",
"vwx", "yz|abc"]]

Some strings contain the pipe character.

I want to delete all the arrows that do NOT contain a certain string.

I tried this:

a.delete_if { |x| !x.include? "ghi|ghi" }

=>

Of course, the array I need would be
=> [["abc", "def", "ghi|ghi|kl"]]

I couldn't figure out a work around. Any wildcards available for string
checking in Ruby? Any ideas?
Thanks.

Cheers,
Chris

Try

a['|']

That will return nil if the string does not contain the pipe.

···

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3

Chris Chris wrote:

Hi,

I have an array a

=> [["abc", "def", "ghi|ghi|kl"], ["jkl", "mno", "ghi|pqr"], ["stu",
"vwx", "yz|abc"]]

Some strings contain the pipe character.

I want to delete all the arrows that do NOT contain a certain string.

I tried this:

a.delete_if { |x| !x.include? "ghi|ghi" }

=>

Of course, the array I need would be
=> [["abc", "def", "ghi|ghi|kl"]]

Enumerable#grep can be helpful here.

a = [["abc", "def", "ghi|ghi|kl"], ["jkl", "mno", "ghi|pqr"], ["stu",
"vwx", "yz|abc"]]

a.delete_if { |x| x.grep(/ghi\|ghi/).empty? }

p a # ==> [["abc", "def", "ghi|ghi|kl"]]

Note that the '|' char needs to be escaped in a regex.

Another option:

a.delete_if { |x| x.all? { |s| not s.include? "ghi|ghi" }}

Closer to the way you phrased the problem, but IMO a little less rubyesque.

···

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       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407

4

Hi --

···

On Mon, 7 Jul 2008, Chris Chris wrote:

Hi,

I have an array a

=> [["abc", "def", "ghi|ghi|kl"], ["jkl", "mno", "ghi|pqr"], ["stu",
"vwx", "yz|abc"]]

Some strings contain the pipe character.

I want to delete all the arrows that do NOT contain a certain string.

I tried this:

a.delete_if { |x| !x.include? "ghi|ghi" }

=>

Of course, the array I need would be
=> [["abc", "def", "ghi|ghi|kl"]]

I couldn't figure out a work around. Any wildcards available for string
checking in Ruby? Any ideas?

Maybe you want this:

   a.delete_if {|ary| !ary.any? {|string| string.include?('ghi|ghi') } }

or something like that.

David

--
Rails training from David A. Black and Ruby Power and Light:
   Intro to Ruby on Rails July 21-24 Edison, NJ
   Advancing With Rails August 18-21 Edison, NJ
See http://www.rubypal.com for details and updates!

5

Hi --

Chris Chris wrote:

Hi,

I have an array a

=> [["abc", "def", "ghi|ghi|kl"], ["jkl", "mno", "ghi|pqr"], ["stu",
"vwx", "yz|abc"]]

Some strings contain the pipe character.

I want to delete all the arrows that do NOT contain a certain string.

I tried this:

a.delete_if { |x| !x.include? "ghi|ghi" }

=>

Of course, the array I need would be
=> [["abc", "def", "ghi|ghi|kl"]]

Enumerable#grep can be helpful here.

a = [["abc", "def", "ghi|ghi|kl"], ["jkl", "mno", "ghi|pqr"], ["stu",
"vwx", "yz|abc"]]

a.delete_if { |x| x.grep(/ghi\|ghi/).empty? }

p a # ==> [["abc", "def", "ghi|ghi|kl"]]

Note that the '|' char needs to be escaped in a regex.

Another option:

a.delete_if { |x| x.all? { |s| not s.include? "ghi|ghi" }}

Closer to the way you phrased the problem, but IMO a little less rubyesque.

I kind of like this hybrid:

def a.delete_unless(&block); replace select(&block); end

=> nil

a.delete_unless {|ary| ary.include? {|string| string.include?("ghi|ghi") }}

=> [["abc", "def", "ghi|ghi|kl"]]

David

···

On Mon, 7 Jul 2008, Joel VanderWerf wrote:

--
Rails training from David A. Black and Ruby Power and Light:
   Intro to Ruby on Rails July 21-24 Edison, NJ
   Advancing With Rails August 18-21 Edison, NJ
See http://www.rubypal.com for details and updates!