Determine if part of a hash key exists

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johnnybutler7

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Mar 11, 2010, 6:13:52 AM3/11/10
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Hi,

I have a hash something like {:schools_name =>
''test", :schools_address => "test, etc....}

What i need to know is does any of the keys contain the word "schools"
in it.

So

hash.has_key? :schools_name will return true

But how can i get it to return true if part of any key contains the
word "schools"

I can think of a couple of ways using a loop but surely there has to
be a quick 1 line way?

JB

Michael Pavling

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Mar 11, 2010, 6:50:03 AM3/11/10
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There's a few things you can do with enumerable methods
(http://ruby-doc.org/core/classes/Enumerable.html) depending on what
you want to know from the match (just whether it's in there somewhere;
exactly where it is; all the keys that match; etc)

Personally, I'd recommend looking at "select" and "detect" methods as
a start, but here's a line using a loop (like you said ;-)
Run this at the console to see all of the positions of the matches shown.

hash.keys.each { |hash_key| puts hash_key.to_s =~ /schools/ }

But I *think* this is what you're after, but if not, hopefully it puts
you on the right track:

hash.keys.select { |hash_key| hash_key.to_s =~ /schools/ }

johnnybutler7

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Mar 11, 2010, 7:05:02 AM3/11/10
to Ruby on Rails: Talk
Ye this is what i had come up with

hash.keys.collect {|k| k.to_s.include?('schools') }

like the regular expression better though,

cheers,

JB


On 11 Mar, 11:50, Michael Pavling <pavl...@gmail.com> wrote:

Pedro Fernandes Steimbruch

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Mar 11, 2010, 6:53:17 AM3/11/10
to rubyonra...@googlegroups.com
h.each_key.collect {|k| k if k.to_s.include?('school') }

irb(main):007:0> h = {:school_name => 'RoR School', :school_address => 'RoR Street'}
=> {:school_name=>"RoR School", :school_address=>"RoR Street"}
irb(main):008:0> h.each_key.collect {|k| k if k.to_s.include?('school') }
=> [:school_name, :school_address]
irb(main):009:0>

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