Question 302845 in Javascript Question posted in
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Javascript – How to find number of occurrences based on input value

I’m attempting to find the number of occurrences based on input value for ownerId in the JavaScript Json Object below. If the ownerId is the number "1" the result should be three since the ownerId appears 3 times.

ownerID: 3

Here is what I have so far…

let inputValue = 1;
let return = "";

const result = jsonResponse.jsonArray[0].info.find(
(arr) => arr.ownderID === inputValue;  );
    
var data = jsonResponse.jsonArray[0].info
        .reduce((counts, result) => {
        const inputItem = result[inputValue];
        counts[inputItem] = (counts[inputItem] || 0) + 1;
        return counts;
      }, {
      });

    return = data;

JSON…

   const jsonResponse = {
   "jsonArray": [
     {
        "info": [
            {
                "ownerId": 1,
                "carType": "Nissan",
                "houseType": "Rancher"
            },
            {
                "ownerId": 1,
                "carType": "Ford",
                "houseType": "Trailer"
            }
        ],
        "familyInfo": {
            "kids": 1,
            "tuition": "yes",
            "parentId": 7
        }
    },
    {
        "info": [
            {
                "ownerId": 3,
                "carType": "Nissan",
                "houseType": "Single"
            }
        ],
        "familyInfo": {
            "kids": 4,
            "tuition": "no",
            "parentId": 11
        }
    },
    {
        "info": [
            {
                "ownerId": 1,
                "carType": "Chevy",
                "houseType": "TownHome"
            }
        ]
    }
  ]
}

Am I going about this the right way using find and reduce?

Tags:

2

Answers


  1. 0

    You are almost there, what you need to do is count across multiple jsonArrays and also within the infos

    Look at the code below, I have commented it appropriately to make it verbose.
    Hope it helps.

    const jsonResponse = {
  "jsonArray": [{
      "info": [{
          "ownerId": 1,
          "carType": "Nissan",
          "houseType": "Rancher"
        },
        {
          "ownerId": 1,
          "carType": "Ford",
          "houseType": "Trailer"
        }
      ],
      "familyInfo": {
        "kids": 1,
        "tuition": "yes",
        "parentId": 7
      }
    },
    {
      "info": [{
        "ownerId": 3,
        "carType": "Nissan",
        "houseType": "Single"
      }],
      "familyInfo": {
        "kids": 4,
        "tuition": "no",
        "parentId": 11
      }
    },
    {
      "info": [{
        "ownerId": 1,
        "carType": "Chevy",
        "houseType": "TownHome"
      }]
    }
  ]
}

// what to search for?
const searchOwnerId = 1;

// reduce to count owner id across multiple items in the list
const counts = jsonResponse.jsonArray.reduce((acc, item) => {
  // count the owner ids inside the infos
  // filter for the ownerId and length works perfect
  
  acc += item.info.filter(
    ({ownerId}) => ownerId == searchOwnerId
  ).length

  return acc

// start reduce with a zero
}, 0);

// final output
console.log(counts)
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  2. 0

    You can also use forEach loop or reduce as given in other answer both method works fine.

    const jsonResponse = {
  jsonArray: [
    {
      info: [
        {
          ownerId: 1,
          carType: "Nissan",
          houseType: "Rancher",
        },
        {
          ownerId: 1,
          carType: "Ford",
          houseType: "Trailer",
        },
      ],
      familyInfo: {
        kids: 1,
        tuition: "yes",
        parentId: 7,
      },
    },
    {
      info: [
        {
          ownerId: 3,
          carType: "Nissan",
          houseType: "Single",
        },
      ],
      familyInfo: {
        kids: 4,
        tuition: "no",
        parentId: 11,
      },
    },
    {
      info: [
        {
          ownerId: 1,
          carType: "Chevy",
          houseType: "TownHome",
        },
      ],
    },
  ],
};
function countOccurrences(jsonResponse, inputValue) {
  let resultCount = 0;

  jsonResponse.jsonArray.forEach((item) => {
    if (item.info) {
      resultCount += item.info.filter(
        (info) => info.ownerId === inputValue
      ).length;
    }
  });

  return resultCount;
}

const inputValue = 1;
const result = countOccurrences(jsonResponse, inputValue);
console.log(result);
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