JSON Parse to Object Weired Results?

Question

I am parsing an json whose structure looks like this:

"records": [
        {
            "timestamp": "1604133302",
            "state": "Andhra Pradesh",
            "district": "Anantapur",
            "market": "Rayadurg",
            "commodity": "Maize",
        },
        {
            "timestamp": "1604133302",
            "state": "Andhra Pradesh",
            "district": "Chittor",
            "market": "Chittoor",
            "commodity": "Maize",
        },
.... 
]

and This is the code i tried to parse to object i want to show them in optional buttions in html where people selects the state and city and all :

jsonFile.records.forEach(function (s) {
    let { state, district, market, commodity } = s;
    // states[state] = district;
    // states[state][district] = market
    // states[state][district][market] = commodity;
    
    states[state] = {
        [district]: {
            [market]: [
                [commodity],
            ]
        }
    };
}); 

It's replacing the last updates.

How to properly parse.

The object structure i want is like this:

{
   "myState":{
      "myDistrict":{
         "myMarket":[
            "commoditynames"
         ],
         "myMarketAnother":[
            "commoditynames"
         ]
      },
      "myDistrictAnother":{
         "myMarket":[
            "commoditynames"
         ],
         "myMarketAnother":[
            "commoditynames"
         ]
      }
   }
} 

How can i parse this properly ?

Answer 1

You just need to push the result not replace in the final commodity array.

We can use .reduce(), we can iterate over every element of an array and can maintain a final state of result. Read more about it Array.prototype.reduce().

On every iteration, we initialize our result with empty objects/array and then finally pushing the desired data.

function fixJSONStructure(records = {}) {
  
  return records.reduce((result, record) => {
      let { state, district, market, commodity } = record;
      
      // initialize with empty object
      if (!result[state]) result[state] = {};
      if (!result[state][district]) result[state][district] = {};
      if (!result[state][district][market]) result[state][district][market] = [];
      
      // pushing a commodity instead of replacing
      result[state][district][market].push(commodity);
      
      return result;
  }, {});
}

records = [
        {
            "timestamp": "1604133302",
            "state": "Andhra Pradesh",
            "district": "Anantapur",
            "market": "Rayadurg",
            "commodity": "Maize",
        },
        {
            "timestamp": "1604133302",
            "state": "Andhra Pradesh",
            "district": "Anantapur",
            "market": "Rayadurg",
            "commodity": "something else",
        },
        {
            "timestamp": "1604133302",
            "state": "Andhra Pradesh",
            "district": "Chittor",
            "market": "Chittoor",
            "commodity": "Maize",
        },
        {
            "timestamp": "1604133302",
            "state": "Karnatka",
            "district": "Bangalore",
            "market": "foobar",
            "commodity": "baz",
        },
];
console.log (fixJSONStructure(records));