Difficult matching of array elements

Question

I got this array:

@array = [["1003", "4"], ["963", "3"], ["1006", "1"], ["1064", "1"], ["1095", "1"], ["963", "http://www.google.com/1"], ["1003", "http://www.google.com/2"]]

and i need this as result:

@array = [["1003", "http://www.google.com/2"], ["963", "http://www.google.com/1"]]

Matching every [0] with each other, if it fits set "http: link" to [1].
Delete all entrys with no matching.

How is this possible?

Gazler · Accepted Answer · 2012-01-06 17:50:46Z

8

Hash[@array].reject{|k,v| v == "1"}.to_a

What this is doing:

Initialize array:

@array => [["1003", "4"], ["963", "3"], ["1006", "1"], ["1064", "1"], ["1095", "1"], ["963", "http://www.google.com/1"], ["1003", "http://www.google.com/2"]]

Convert to hash:

hash = Hash[@array] => {"1003"=>"http://www.google.com/2", "963"=>"http://www.google.com/1", "1006"=>"1", "1064"=>"1", "1095"=>"1"}

Remove where the value is == "1":

hash = hash.reject!{|k,v| v == "1"} => {"1003"=>"http://www.google.com/2", "963"=>"http://www.google.com/1"}

Convert back to array:

hash.to_a => [["1003", "http://www.google.com/2"], ["963", "http://www.google.com/1"]]

reject is an alias of delete_if

answered Jan 6, 2012 at 17:50

Gazler

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2 Comments

ian Over a year ago

you need a to_a on the end to match the OP's output.

Dave Newton Over a year ago

With an additional to_a at the end so it's in the array format OP asked for.

Mario Visic · Accepted Answer · 2012-01-06 17:55:56Z

0

magic!

@array = [["1003", "4"], ["963", "3"], ["1006", "1"], ["1064", "1"], ["1095", "1"], ["963", "http://www.google.com/1"], ["1003", "http://www.google.com/2"]] 

@links = @array.select { |item| item[1].match(/http/)}
@non_links = @array - @links
@non_links.map do |non_link|
  if @links.map(&:first).include? non_link.first
    [non_link.first, @links.select { |link| link.first == non_link.first }.first.last]
  end
end.compact

answered Jan 6, 2012 at 17:55

Mario Visic

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2 Comments

SG 86 Over a year ago

Thx, this "@links = @array.select { |item| item[1].match(/http/)} " was extremly helpful for me!!

Mario Visic Over a year ago

No problems. You could combine that with the top ander and use something like Hash[@array].select{|k,v| v.match(/http/)}.to_a should work :)

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