hash assignment when (key => value) are stored in an array? (ruby)

Question

I have hash (@post) of hashes where I want to keep the order of the hash's keys in the array (@post_csv_order) and also want to keep the relationship key => value in the array.

I don't know the final number of both @post hashes and key => value elements in the array.

I don't know how to assign the hash in a loop for all elements in the array. One by one @post_csv_order[0][0] => @post_csv_order[0][1] works nicely.

#  require 'rubygems'
require 'pp'

@post = {}

forum_id = 123           #only sample values.... to make this sample script work
post_title = "Test post"

@post_csv_order = [
  ["ForumID" , forum_id],
  ["Post title", post_title]  
]

if @post[forum_id] == nil
  @post[forum_id] = {
    @post_csv_order[0][0] => @post_csv_order[0][1],
    @post_csv_order[1][0] => @post_csv_order[1][1]
    #@post_csv_order.map {|element| element[0] => element[1]}
    #@post_csv_order.each_index {|index|        @post_csv_order[index][0] => @post_csv_order[index][1] }
  }
end

pp @post

desired hash assignment should be like that

{123=>{"Post title"=>"Test post", "ForumID"=>123}}

Answer 1

The best way is to use to_h:

[ [:foo,1],[:bar,2],[:baz,3] ].to_h  #=> {:foo => 1, :bar => 2, :baz => 3}

Note: This was introduced in Ruby 2.1.0. For older Ruby, you can use my backports gem and require 'backports/2.1.0/array/to_h', or else use Hash[]:

array = [[:foo,1],[:bar,2],[:baz,3]]
# then
Hash[ array ]  #= > {:foo => 1, :bar => 2, :baz => 3}

This is available in Ruby 1.8.7 and later. If you are still using Ruby 1.8.6 you could require "backports/1.8.7/hash/constructor", but you might as well use the to_h backport.