title: Iterate through nested JSON object array and store as key-value pair
body: <p>I have to iterate through this JSON:</p>
  
  <pre><code>{
    "data": 321563,
    "group": [
      {
        "added": 42421,
        "normal": {
          "x": 39,
          "y": "0.1300",
          "b": "0.4326",
          "c": "0.0552",
          "f": 166833
        },
        "j": "240313",
        "b": "0.2251",
        "a": "dda",
        "b": "0.101",
        "a": 922,
        "f": {
          "c": 39,
          "d": "0.263",
          "a": "2.8955",
          "h": "0.3211",
          "d": 274
        },
        "a": false,
        "k": 5,
        "w": "0.072",
        "d": "0.045",
        "e": 3
      },
  </code></pre>
  
  <p>I only want the j and k stored like a key value pair e.g. <code>"j":k</code></p>
  
  <p>I need to loop all of it, and store it to a file.</p>