Eliminating duplicates in an array of objects and calculating the sum of a specific key using JavaScript

Question

Eliminating duplicates in an array of objects and calculating the sum of a specific key using JavaScript

In my JavaScript code, I have an object called obj. I am trying to figure out how to remove duplicates in the info array and calculate the sum of the quantities (qty) for each unique key. Can you help me with this problem?

function updateTotalQuantity(obj) {
  return obj.map(item => ({
    ...item,
    total: item.info.reduce((acc, curr) => acc + curr.qty, 0)
  }));
}

var obj = [
 {id:1, info:[{idx:1, qty: 1}, {idx:2, qty: 2},{idx:2, qty: 2}], code: "sample1", total: 1},
 {id:2, info:[{idx:3, qty: 2}, {idx:4, qty: 2}], code: "sample2", total: 2}
]

Desired Result:

[
 {id:1, info:[{idx:1, qty: 1}, {idx:2, qty: 2}], code: "sample1", total: 3},
 {id:2, info:[{idx:3, qty: 2}, {idx:4, qty: 2}], code: "sample2", total: 4}
]

javascript arrays object nested-object

Answer 1

Answer №1

To streamline the data and remove any duplicate entries in rows, you can utilize the reduce method along with the Map function:

var details =[
 {id:1, information:[{index:1, quantity: 1},{index:2, quantity: 2},{index:2, quantity: 2}], code: "example1", total: 1},
 {id:2, information:[{index:3, quantity: 2}, {index:4, quantity: 2}], code: "example2", total: 2}
];

var outcome = details.reduce((accumulator, item)=>{
    item.information = [...new Map(item.information.map(i=>[i.index, i])).values()];
    item.total = item.information.reduce((sum, {quantity})=>sum+quantity,0);
    accumulator = [...accumulator, item];
    return accumulator;
},[]);

console.log(outcome);

Answer 2

To streamline the data and remove any duplicate entries in rows, you can utilize the reduce method along with the Map function:

var details =[
 {id:1, information:[{index:1, quantity: 1},{index:2, quantity: 2},{index:2, quantity: 2}], code: "example1", total: 1},
 {id:2, information:[{index:3, quantity: 2}, {index:4, quantity: 2}], code: "example2", total: 2}
];

var outcome = details.reduce((accumulator, item)=>{
    item.information = [...new Map(item.information.map(i=>[i.index, i])).values()];
    item.total = item.information.reduce((sum, {quantity})=>sum+quantity,0);
    accumulator = [...accumulator, item];
    return accumulator;
},[]);

console.log(outcome);

Answer 3

Answer №2

Give this example a shot, even though my outcome doesn't match the expected results. Give it a try

const data = [
  {
    id: 1,
    info: [
      { idx: 1, qty: 1 },
      { idx: 2, qty: 2 },
      { idx: 2, qty: 2 },
    ],
    code: "sample1",
    total: 1,
  },
  {
    id: 2,
    info: [
      { idx: 3, qty: 2 },
      { idx: 4, qty: 2 },
    ],
    code: "sample2",
    total: 2,
  },
];

let result = data.map((entry) => {
  return {
    ...entry,
    info: entry.info.reduce((prev, curr) => {
      const item = prev.find(
        (element) => element.idx === curr.idx && element.qty == curr.qty
      );

      if (!item) {
        prev = [...prev, curr];
      }

      return prev;
    }, []),
  };
});

result = result.map((entry) => {
  return {
    ...entry,
    total: entry.total + entry.info.reduce((prev, curr) => prev + curr.qty, 0),
  };
});

console.dir(result, { depth: null, color: true });

Check out

Answer 4

Give this example a shot, even though my outcome doesn't match the expected results. Give it a try

const data = [
  {
    id: 1,
    info: [
      { idx: 1, qty: 1 },
      { idx: 2, qty: 2 },
      { idx: 2, qty: 2 },
    ],
    code: "sample1",
    total: 1,
  },
  {
    id: 2,
    info: [
      { idx: 3, qty: 2 },
      { idx: 4, qty: 2 },
    ],
    code: "sample2",
    total: 2,
  },
];

let result = data.map((entry) => {
  return {
    ...entry,
    info: entry.info.reduce((prev, curr) => {
      const item = prev.find(
        (element) => element.idx === curr.idx && element.qty == curr.qty
      );

      if (!item) {
        prev = [...prev, curr];
      }

      return prev;
    }, []),
  };
});

result = result.map((entry) => {
  return {
    ...entry,
    total: entry.total + entry.info.reduce((prev, curr) => prev + curr.qty, 0),
  };
});

console.dir(result, { depth: null, color: true });

Check out

Answer 5

Answer №3

function updatedList(data) {
    return data.map(item => ({
        ...item,
        ...modifyData(item.data)
    }));
}

function modifyData(arr) {
    return arr.reduce((acc, cur) => {
        acc.data = acc.data || [];
        acc.total = acc.total || 0;
        if (!acc.data.some(elem => cur.id === elem.id && cur.quantity === elem.quantity)) {
            acc.data.push(cur);
            acc.total += cur.quantity;
        }
        return acc;
    }, {});
}

var data = [
    { id: 1, data: [{ id: 1, quantity: 1 }, { id: 2, quantity: 2 }, { id: 2, quantity: 2 }], code: "alpha", total: 1 },
    { id: 2, data: [{ id: 3, quantity: 2 }, { id: 4, quantity: 2 }], code: "beta", total: 2 }
]

console.log(JSON.stringify(updatedList(data)));

Answer 6

function updatedList(data) {
    return data.map(item => ({
        ...item,
        ...modifyData(item.data)
    }));
}

function modifyData(arr) {
    return arr.reduce((acc, cur) => {
        acc.data = acc.data || [];
        acc.total = acc.total || 0;
        if (!acc.data.some(elem => cur.id === elem.id && cur.quantity === elem.quantity)) {
            acc.data.push(cur);
            acc.total += cur.quantity;
        }
        return acc;
    }, {});
}

var data = [
    { id: 1, data: [{ id: 1, quantity: 1 }, { id: 2, quantity: 2 }, { id: 2, quantity: 2 }], code: "alpha", total: 1 },
    { id: 2, data: [{ id: 3, quantity: 2 }, { id: 4, quantity: 2 }], code: "beta", total: 2 }
]

console.log(JSON.stringify(updatedList(data)));

Eliminating duplicates in an array of objects and calculating the sum of a specific key using JavaScript

Answer №1

Answer №2

Answer №3

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