Question

I am trying to do a little experiment which has me stumped at the moment.

I create the new Hash

tt = Hash.new()

Then I add two hashes inside with keys:

tt.merge!(:in => Hash.new)
tt.merge!(:out => Hash.new)

So I have a hash that looks like this:

{
     :in => {},
    :out => {}
}

Now I have another hash of hashes called res that I iterate through and perform an IF statement on each one:

res.each do  |x|
    if x[:id] == nil
        tt[:out].merge!(x)
    else 
        tt[:in].merge!(x)
end 
end

However this only attaches the last value of the previous hash to both out and in inside the new hash.

What I am trying to do is use the IF statement to put new hashes under the key of IN or OUT

So it ends up looking like:

{
     :in => {{:1 => 1 ,:2 => 1 ,:3 => 1 ,:4 => 1 ,:5 => 1 },{:1 => 1 ,:2 => 1 ,:3 => 1 ,:4 => 1 ,:5 => 1 }},
    :out => {{:1 => 1 ,:2 => 1 ,:3 => 1 ,:4 => 1 ,:5 => 1 }, {:1 => 1 ,:2 => 1 ,:3 => 1 ,:4 => 1 ,:5 => 1 }}
}

Also – should I be using Hashes for this or arrays?? I want to export it eventually as JSON.

For example, this works. But not sure if it is right:

tt = Hash.new(:in => Hash.new, :out => Hash.new)
tt.merge!(:in => Array.new)
tt.merge!(:out => Array.new)
ap tt.class
res.each do  |x|
    if x[:id] == nil
        tt[:out] << x   
    else 
        tt[:in] << x
end 
end

Thnaks

Answer 1

This isn’t possible. You’re talking about {1,2,3,4,5} as a hash, but it’s not a hash, it’s an array. If you don’t have specific keys to associate with values, you don’t have hash-like data. Your second version which uses arrays is correct (except for your use of merge… see below).

Also, if you want to add something to a hash, you should use the [] operator, not repeatedly use merge.

For example, this is wrong:

tt = Hash.new()
tt.merge!(:in => Hash.new)
tt.merge!(:out => Hash.new)

What you want is either this:

tt = Hash.new()
tt[:in] = Hash.new
tt[:out] = Hash.new

or better, this:

tt = { in: {}, out: {} }

The full and correct version of this could would look something like this:

tt = Hash.new(in: [], out: [])

res.each do  |x|
  if x[:id].nil?
    tt[:out] << x   
  else 
    tt[:in] << x
end