Json.NET parse array in object

Question

I'm having an extremely difficult time parsing multiple arrays out of an array, embedded in several object in JSON.

Basically the json looks like

{
 took:8,
 success:true,
 items:[
  keywords:{...},
  mainInfo:{
    name:'...',
    expDate:'...',
    targetCities:[...],
    targetStates:[...]
  },
  additionalInfo:{
    skills:[],
    homeTime:''
  }
}

My C# looks like:

public class Job{
  public string name{get;set;}
  public List<string> targetCities{get;set;}
  public List<string> targetStates{get;set;}
  public List<string> skills{get;set;}
  public string homeTime{get;set;}
}
public class Jobs{
  private JObject o;
  private List<Job> jobs;
  public Jobs(string json){
    this.o=JObject.Parse(json);
  }
  public List<Job> toList(){
    List<JObject> allJobs=o["items"].Select(t => (JObject)t).ToList();
    foreach(JObject i in allJobs){
      Job j=new Job();
      j.name=(string)i["mainInfo"]["name"];
      j.targetCities=i["mainInfo"]["targetCities"].Select(t =>(string)t).ToList();
      j.targetStates=i["mainInfo"]["targetStates"].Select(t =>(string)t).ToList();
      j.expDate=(string)i["mainInfo"]["expDate"]
      j.skills=i["additionalInfo"]["skills"].Select(t =>(string)t).ToList();
      j.homeTime=(string)i["additionalInfo"]["homeTime"];
      this.jobs.Add(j); //ERROR
    }
    return this.jobs;
}

The error is a Null Reference Exception , with the info Object reference not set to an instance of an object. , however it seems that this error jumps around almost unpredictably as I try and change my code to fix the bug.

I am by no means a C# or .NET expert. I had dealt with the language in the past, but I personally do not like it. So forgive me for any stupid error I may have made.

ADDITION:

I'm basically stepping through all the items and trying to create a Job object from each item using the data accordingly.

Answer 1

You forgot to initialize your jobs field, private List<Job> jobs; You don't need this private field if you alway generate the jobs list. Use a local variable.

public List<Job> toList()
        {
            jobs = new List<Job>(); //add this line
            List<JObject> allJobs = o["items"].Select(t => (JObject)t).ToList();
            foreach (JObject i in allJobs)
            {
                Job j = new Job();
                j.name = (string)i["mainInfo"]["name"];
                j.targetCities = i["mainInfo"]["targetCities"].Select(t => (string)t).ToList();
                j.targetStates = i["mainInfo"]["targetStates"].Select(t => (string)t).ToList();
                j.expDate = (string)i["mainInfo"]["expDate"];
                j.skills = i["additionalInfo"]["skills"].Select(t => (string)t).ToList();
                j.homeTime = (string)i["additionalInfo"]["homeTime"];
                this.jobs.Add(j); 
            }
            return this.jobs;
        }

Answer 2

I think that you may define allJobs first

List<JObject> allJobs = new List<JObject>();
allJobs=o["items"].Select(t => (JObject)t).ToList();