Ways to convert JavaScript object to hashmap

Question

Ways to convert JavaScript object to hashmap

I am attempting to generate a map of type <String, Array()> from a JSON object. Suppose I have the following JSON structure:

[
    {
        "userId": "123123",
        "password": "fafafa",
        "age": "21"
    },
    {
        "userId": "321321",
        "password": "nana123",
        "age": "34"
    }
]

The desired map should have the format:

key (string), value (array)

{
    "userId": [
        "123123",
        "321321"
    ],
    "password": [
        "fafafa",
        "nana123"
    ],
    "age": [
        "21",
        "34"
    ]
}

Would it be possible to achieve this? :/

Many thanks in advance.

javascript json dictionary

Answer 1

Answer №1

Demo

var data = '[{"productId" : "987", "price": "50", "quantity": "2"}, {"productId" : "654", "price" : "30", "quantity" : "1"}]';

var items = JSON.parse(data);
var result = {};

for(var j=0; j<items.length; j++)
{
    for(var itemKey in items[j])
    {
        if(items[j].hasOwnProperty(itemKey))
        {
            if(typeof result[itemKey] == 'undefined')
            {
                result[itemKey] = [];
            }
            result[itemKey].push(items[j][itemKey]);
        }
    }
}

document.write(JSON.stringify(result));

Generated Output:

{"productId":["987","654"],"price":["50","30"],"quantity":["2","1"]}

Answer 2

Demo

var data = '[{"productId" : "987", "price": "50", "quantity": "2"}, {"productId" : "654", "price" : "30", "quantity" : "1"}]';

var items = JSON.parse(data);
var result = {};

for(var j=0; j<items.length; j++)
{
    for(var itemKey in items[j])
    {
        if(items[j].hasOwnProperty(itemKey))
        {
            if(typeof result[itemKey] == 'undefined')
            {
                result[itemKey] = [];
            }
            result[itemKey].push(items[j][itemKey]);
        }
    }
}

document.write(JSON.stringify(result));

Generated Output:

{"productId":["987","654"],"price":["50","30"],"quantity":["2","1"]}

Answer 3

Answer №2

function mergeObjectsProperties(inputArr) {
  return inputArr.reduce(function(accumulator, currentObj) { // Iterate through each object in the array.
    Object.keys(currentObj).forEach(function(key) { // Iterate through each key in the current object.
      if (!(key in accumulator)) { accumulator[key] = []; } // Create an empty array for the key if it doesn't exist.
      accumulator[key].push(currentObj[key]); // Add the property value to the corresponding key's array in the accumulator.
    });
    return accumulator;
  }, {});
}

var jsonData = '[{"userId" : "123123", "password": "fafafa", "age": "21"}, {"userId" : "321321", "password" : "nana123", "age" : "34"}]';

mergeObjectsProperties(JSON.parse(jsonData));
// {
//   "userId": ["123123", "321321"],
//   "password": ["fafafa", "nana123"],
//   "age": ["21", "34"]
// }

Answer 4

function mergeObjectsProperties(inputArr) {
  return inputArr.reduce(function(accumulator, currentObj) { // Iterate through each object in the array.
    Object.keys(currentObj).forEach(function(key) { // Iterate through each key in the current object.
      if (!(key in accumulator)) { accumulator[key] = []; } // Create an empty array for the key if it doesn't exist.
      accumulator[key].push(currentObj[key]); // Add the property value to the corresponding key's array in the accumulator.
    });
    return accumulator;
  }, {});
}

var jsonData = '[{"userId" : "123123", "password": "fafafa", "age": "21"}, {"userId" : "321321", "password" : "nana123", "age" : "34"}]';

mergeObjectsProperties(JSON.parse(jsonData));
// {
//   "userId": ["123123", "321321"],
//   "password": ["fafafa", "nana123"],
//   "age": ["21", "34"]
// }

Answer 5

Answer №3

By using Javascript's JSON.stringify method, you can easily transform a JSON compatible object structure into a JSON string.

Answer 6

By using Javascript's JSON.stringify method, you can easily transform a JSON compatible object structure into a JSON string.

Ways to convert JavaScript object to hashmap

Answer №1

Answer №2

Answer №3

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