Ruby, turn array of hashes into single hash

I have the following Array of Hashes:

a = [{:a => 1, :b => "x"}, {:a => 2, :b => "y"}]

I need to turn it into:

z={"x" => 1, "y" => 2} 

or:

z={1 => "x", 2 => "y"}

Can I do this in a clean & functional way?

Something like this:

Hash[a.map(&:values)] # => {1=>"x", 2=>"y"}

if you want the other way:

Hash[a.map(&:values).map(&:reverse)] # => {"x"=>1, "y"=>2}

incorporating the suggestion from @squiguy:

Hash[a.map(&:values)].invert

To display the searched item in the same page

The following code present in srches_controller

def index   @srches = Srch.all   respond_to do |format|     format.html # index.html.erb     format.json { render :json => @srches }end. ..def search    @srch=Srch.find(:all,                :conditions => ["name LIKE ? OR address LIKE ?", "%#{params[:search]}%", "%#{params[:search]}%"])end

The searched item is now displayed in the new search page.
But I need to display the searched item in the same index page.
What is the solution?

You can pass parameter search to index page & search your results with:

def index  @srches = Srch.scoped  if params[:search].present?    @srches = @srches.where(['name LIKE ? OR address LIKE ?', "%#{params[:search]}%", "%#{params[:search]}%"])  end  respond_to do |format|    format.html    format.json { render :json => @srches }  endend

or you can set scope in your model:

scope :search, lambda{|query|  if query.present?    where(['name LIKE ? OR address LIKE ?', "%#{query}%", "%#{query}%"])  end}

and call it in controller with:

@srches = Srch.search(params[:search])

rails input selected values from params to select_tag (multiple => true)

I want to keep the select_tag(:multiple => true) options to be selected which were selected by user once search is performed

<%= select_tag 'values[]', method_for_options_for_select, :class => 'some-class', :multiple => true, :size => 6 %>

Suppose a user select 4 values from the select tag then for values should be selected,
How can we pass this 4 values to the select_tag?

I tried using :selected => params['values[]'] yet this doesnt works for multiple true

Any assist will be appreciated

Ref this & options_for_select

Something like following

<%= select_tag 'values[]', options_for_select(@stores.map {|s| [s.store_name, s.store_id]}, @user.stores.map {|j| j.store_id}),:class => 'some-class', :multiple => true, :size => 6 %>