Better way to fill a Ruby hash?

Is there a better way to do this? (it looks clunky)

form_params = {}
form_params['tid'] = tid
form_params['qid'] = qid
form_params['pri'] = pri
form_params['sec'] = sec
form_params['to_u'] = to_u
form_params['to_d'] = to_d
form_params['from'] = from
form_params['wl'] = wl

From stackoverflow

• form_params = { "tid" => tid, "qid" => qid }
  

  Or you could do

  form_params = Hash["tid", tid, "qid", qid]       #=> {"tid"=>tid, "qid"=>qid}
  form_params = Hash["tid" => tid, "qid" => qid]   #=> {"tid"=>tid, "qid"=>qid}
  form_params = Hash[tid => tid, qid => qid]       #=> {"tid"=>tid, "qid"=>qid}
  

  (nb. the last one is new for 1.9 and it makes your key symbols instead of strings)

  {tid:tid, qid:qid}

  Keys and values occur in pairs, so there must be an even number of arguments.

  Chuck : As of Ruby 1.9, if you're OK with the keys being symbols rather than strings, you can also say {tid:tid, qid:qid}.

  Schildmeijer : : doesn't work, => does

  Chuck : No, the colon works just as I said. I just tested. ruby -e "tid=12; puts({tid:tid})" prints "{:tid=>12}". The => form does not work -- it prints {12=>12}.

  Schildmeijer : aha, now I see the different

  kolrie : Side note: the "hash from arrays" method won't work on 1.9.

• If performance is not important this one might look better:

  form_params = {}
  ['tid', 'qid', 'pri', 'sec', 'to_u', 'to_d', 'from', 'wl'].each do |v|
    form_params[v] = eval(v)
  end
  

  If those names are actually methods you can replace eval by the faster send:

  form_params[v] = send(v.to_sym)
  

  (Update) An alternative (and more elegant) way using inject:

  form_params = ['tid', 'qid', 'pri', 'sec', 'to_u', 'to_d', 'from', 'wl'].inject({}) { |h, v| h[v] = send(v); h }
  

• I created a custom class called MoreOpenStruct to deal with Hash's lack of aesthetics, and using that class, your example would look like:

  form_params = MoreOpenStruct.new
  form_params.tid = tid
  form_params.qid = qid
  form_params.pri = pri
  form_params.sec = sec
  form_params.to_u = to_u
  form_params.to_d = to_d
  form_params.from = from
  form_params.wl = wl
  
  form_params_hash = form_params._to_hash
    #=> { :tid => tid, :qid => qid, etc }
  

  If you need string literals rather than symbols as the key to your hash then a couple more tweaks are required.

  I use my custom struct class when I want easy to read/manipulate Hashes, but if all you're doing is an assignment and don't need to parse the hash beyond that, I'd use Roger's solution.

• Slight modification to the above, since your example had string keys:

  form_params = {}
  %w(tid qid pri sec to_u to_d from wl).each{|v| form_params[v] = send(v)}
  

• The other options would be to create a Struct based class to store those values in. For example:

  FormParams = Struct.new(:tid, :qid, :pri, :sec, :to_u, :to_d, :from, :wl)
  

  Then you'd be able to initialise the form_params instance in a variety of ways:

  form_params = FormParams.new(:tid => tid, :qid => qid, # etc ...
  form_params = FormParams.new(tid, qid, pri, sec, to_u, to_d, from, wl)
  form_params = FormParams.new
  form_params.tid = tid
  form_params.gid = gid
  # etc ...