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Groups > comp.lang.ruby > #4725

Re: Linux utility with reverse index facility?

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unknown wrote in post #998974:
> awk &stuff can "give me the the Nth element",
> but, without writing your own search-loop,
> what can "give me the index of the 'element'
> which is <elementValue>" ?
>
> I think it's called 'reverse indexing' ?
>
> == TIA.

>> a = ["foo","bar","baz"]   # note: indexes are 0,1,2
=> ["foo", "bar", "baz"]
>> a.index("bar")
=> 1
>> a.grep(/ba/)
=> ["bar", "baz"]
>> a.each_with_index.select { |line,n| line =~ /ba/ }
=> [["bar", 1], ["baz", 2]]

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Linux utility with reverse index facility? no.top.post@gmail.com - 2011-05-16 10:38 +0000
  Re: Linux utility with reverse index facility? pk <pk@pk.invalid> - 2011-05-16 11:41 +0100
  Re: Linux utility with reverse index facility? Robert Klemme <shortcutter@googlemail.com> - 2011-05-16 05:45 -0500
  Re: Linux utility with reverse index facility? "Chris F.A. Johnson" <cfajohnson@gmail.com> - 2011-05-16 07:59 -0400
    Re (2): Linux utility with reverse index facility? no.top.post@gmail.com - 2011-05-16 19:30 +0000
      Re: Re (2): Linux utility with reverse index facility? "Chris F.A. Johnson" <cfajohnson@gmail.com> - 2011-05-16 15:59 -0400
      Re: Re (2): Linux utility with reverse index facility? Robert Klemme <shortcutter@googlemail.com> - 2011-05-17 02:14 -0500
  Re: Linux utility with reverse index facility? David Brown <david@westcontrol.removethisbit.com> - 2011-05-16 14:38 +0200
    Re: Linux utility with reverse index facility? Robert Klemme <shortcutter@googlemail.com> - 2011-05-16 08:10 -0500
  Re: Linux utility with reverse index facility? Janis Papanagnou <janis_papanagnou@hotmail.com> - 2011-05-16 15:08 +0200
  Re: Linux utility with reverse index facility? Stu <stu@rubyprogrammer.net> - 2011-05-16 12:52 -0500
  Re: Linux utility with reverse index facility? Robert Nichols <SEE_SIGNATURE@localhost.localdomain.invalid> - 2011-05-17 22:40 -0500
    Re: Linux utility with reverse index facility? Luuk <Luuk@invalid.lan> - 2011-05-18 19:14 +0200
    Re: Linux utility with reverse index facility? Ed Morton <mortonspam@gmail.com> - 2011-05-19 16:15 -0700
  Re: Linux utility with reverse index facility? Brian Candler <b.candler@pobox.com> - 2011-05-18 03:14 -0500

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