如何为参数哈希创建数组

Question

In my rails controller I'm getting JSON posted to it that contains a person's work history. So they could have multiple jobs. The jobs are in a format like...

"values": 
[
  {
    "title": "dummy position",
    "company": "company 1",
    "location": "Indianapolis, IN",
    "description": "dummy job description",
    "startDateMonth": "05",
    "startDateYear": "2015",
    "endDateMonth": "06",
    "endDateYear": "2015"
  },
  {
    "title": "dummy position 2",
    "company": "company 2",
    "location": "Indianapolis, IN",
    "description": "dummy job description 2",
    "startDateMonth": "02",
    "startDateYear": "2015",
    "endDateMonth": "05",
    "endDateYear": "2015"
  },
  {
    "title": "dummy position 3",
    "company": "company 3",
    "location": "Indianapolis, IN",
    "description": "dummy job description 3",
    "startDateMonth": "05",
    "startDateYear": "2013",
    "endDateMonth": "02",
    "endDateYear": "2015"
  }
]

I'm trying to add these to the params collection that I can later iterate through in an application class and add these work histories. I have the following code but it doesn't work - NoMethodError - undefined method `[]' for nil:NilClass: for this line params[:job_title][i] = jobs[i]['title']. It was just a guess, as I'm not great in ruby, so is there a way to make this work?

if job_count.numeric?
  jobs = params['positions']['values']
  for i in 0..job_count.to_i
    params[:job_title][i] = jobs[i]['title']
    params[:job_company_name][i] = jobs[i]['company']
    params[:job_start_date][i] = jobs[i]['startDateMonth'] + '/1/' + jobs[i]['startDateYear']
    params[:job_end_date][i] = jobs[i]['endDateMonth'] + '/1/' + jobs[i]['endDateYear']
    params[:job_description][i] = jobs[i]['description']
  end
end

EDIT: This ended up working.

i = 0
jobs.each do | k, work_history |
  i = i + 1
  params['job_title_' + i.to_s] = work_history['title']
  params['job_company_name_' + i.to_s] = work_history['company']
  params['job_start_date_' + i.to_s] = work_history['startDateMonth'] + '/1/' + work_history['startDateYear']
  params['job_end_date_' + i.to_s] = work_history['endDateMonth'] + '/1/' + work_history['endDateYear']
  params['job_description_' + i.to_s] = work_history['description']
end

Answer 1

You get this error because you're trying to do ["title"] on nil , as said, and jobs[i] is probably nil because job_count is wrong.

If you have 3 jobs, and job_count == 3 , your for loop will do 0, 1, 2, 3. However, jobs[3] is rightfully nil.

Try replacing that for with for i in 0..(job_count.to_i - 1)