Null Reference exception when loading json data to dictionary

i am trying to load a json file into a dictionary but i get a NullReferenceException error anytime it gets to the for loop. Here is the code I am using for loading the json file

using UnityEngine;
using UnityEngine.UI;
using System.IO;
using System.Collections;
using System.Collections.Generic;

public class CategoryController : MonoBehaviour {
    private Dictionary<string, string> wordDictionary;
    private string fileName = "testdictionary.json";

    void Start () {
        LoadGameDictionary();
	}
    void LoadGameDictionary()
    {
        wordDictionary = new Dictionary<string, string>();
        string filePath = Path.Combine(Application.streamingAssetsPath, fileName);

        if (File.Exists(filePath))
        {
            Debug.Log("File found");
            string dataAsJson = File.ReadAllText(filePath);
            WordsData wordData = JsonUtility.FromJson<WordsData>(dataAsJson);
            for (int i = 0; i < wordData.items.Length; i++) 
            {
               wordDictionary.Add(wordData.items _.key, wordData.items *.value)*_

}

}
else
{
Debug.LogError(“file not found”);
}
}
}
these are the data classes i am using
[System.Serializable]
public class WordItems
{
public string word;
public string meaning;
}

[System.Serializable]
public class WordsData{
public WordItems[] items;
}
thank you in advance…

Well, how does your JSON file look like? It has to look like this:

{
    "items":[
        {
            "word":"someWordHere",
            "meaning":"some meaning here"
        },
        {
            "word":"someOtherWordHere",
            "meaning":"some other meaning here"
        },
    ]
}

If your JSON doesn’t look like this you can’t load it into that datastructure.