```
def job_ids
 {
   job_id:   r.job_id,
   job_2_id: r.job_2_id,
   job_3_id: r.job_3_id
 }
end

def available_job_id
   job_ids.find { |_k, v| v.nil? }[0].to_s
end

```

im checking which key has the first value of `nil`,and then i convert it to string.

what's the best way to do it? 

This seems to be dirty?

`job_ids.find { |_k, v| v.nil? }[0].to_s`

UPDATE:
here's the desired output so far...

```
[79] pry(main)> job_ids.find{|k, v| v.nil?}[0].to_s
=> "job_2_id"

```