Question 171170 in Javascript Question posted in
A very good W3school tutorial can be found here.

“How can I reorganize objects in Javascript by the same value?”

I have 3 objects

[
{name: 3, q: 10, b: 1},
{name: 5, q: 6, b: 2},
{name: 5, q: 7, b: 1}
]

I need to group them by name:

[
{name: 3: items: [{q:10, b: 1}]},
{name: 5: items: [{q:6, b: 2}, {q:7, b: 1}]},
]

maybe there are any delicate solutions with lodash?

Tags:

4

Answers


  1. 0

    You can use Object.values combined with Array.prototype.reduce() and Array.prototype.push()

    Code:

    const data = [
  { name: 3, q: 10, b: 1 },
  { name: 5, q: 6, b: 2 },
  { name: 5, q: 7, b: 1 },
]

const groupedData = Object.values(
  data.reduce((acc, obj) => {
    const { name, ...rest } = obj
    acc[name] = acc[name] || { name, items: [] }
    acc[name].items.push(rest)
    return acc
  }, {})
)

console.log(groupedData)
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  2. 0

    You dont need lodash, you can just use JavaScript

    const inputArray = [
  {name: 3, q: 10, b: 1},
  {name: 5, q: 6, b: 2},
  {name: 5, q: 7, b: 1}
];

    using forEach

    function groupItemsByName(array) {
  // create a groups to store your new items
  const groups = {};
  
  //loop through your array
  array.forEach(obj => {
    // destructure each object into name and the rest 
    const { name, ...rest } = obj;
    // if the named group doesnt exist create that name with an empty array
    if (!groups[name]) {
      groups[name] = { name, items: [] };
    }
    // add the items to the named group based on the name
    groups[name].items.push(rest);
  });

  return Object.values(groups);
}

const transformedArray = groupItemsByName(inputArray);

    using reduce and Object.values()

    function groupItemsByName(array) {
  //Object.values returns an objects values as an array  
  return Object.values(
    array.reduce((groups, obj) => {
      // destructure as in the forEach method
      const { name, ...rest } = obj;
      // create the groups like in the previous method
      groups[name] = groups[name] || { name, items: [] };
      // push the items to the group based on the name
      groups[name].items.push(rest);
      return groups;
    }, {})
  );
}


const transformedArray = groupItemsByName(inputArray);

    using map and reduce

    const transformedArray = Array.from(
  inputArray.reduce((map, obj) => {
    const { name, ...rest } = obj;
    const existing = map.get(name) || { name, items: [] };
    existing.items.push(rest);
    return map.set(name, existing);
  }, new Map()).values()
);

    output

    console.log(transformedArray);
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  3. 0

    You can use the following simple solution to achieve this.

    const originalArr = [//This is your original input array
    { name: 3, q: 10, b: 1 },
    { name: 5, q: 6, b: 2 },
    { name: 5, q: 7, b: 1 }
];
let filteredArr = [];
originalArr.forEach(el => {
    const index = filteredArr.findIndex(__el => __el.name == el.name);
    if (index == -1) {//This means the current element does not exists in filtered array
        filteredArr.push({ name: el.name, items: [{ q: el.q, b: el.b }] });
    } else {
        filteredArr[index].items.push({ q: el.q, b: el.b });
    }
});
console.log(filteredArr);//You will get your desired output
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  4. 0

    Hello simply you can use for loop with find function.

    i will try to help you Please check below example

    let mainArr = [
    { name: 3, q: 10, b: 1 },
    { name: 5, q: 6, b: 2 },
    { name: 5, q: 7, b: 1 },
];

let setArr = [];

for (let arr of mainArr) {
    let checkValue = setArr.find((e) => e.name.toString() === arr.name.toString());

    if (!checkValue) {
        setArr.push({ name: arr.name, items: [{ q: arr.q, b: arr.b }] });
    } else {
        checkValue.items.push({ q: arr.q, b: arr.b });
    }
}

console.log(JSON.stringify(setArr, null, 2));

Result: [
    { name: 3, items: [{ q: 10, b: 1 }] },
    {
        name: 5,
        items: [
            { q: 6, b: 2 },
            { q: 7, b: 1 },
        ],
    },
];

    I hope this help you

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