Hi am trying to find similar value of this array object and calculate the some of sold for each same values

const sold = [
  { matri: 1, year: 2019, sold: 5 },
  { matri: 2, year: 2020, sold: 3 },
  { matri: 1, year: 2020, sold: 7 },
];

above i have one array object the expected output

{ matri: 1, year: 2020, sold: 5 },
{ matri: 1, year: 2020, sold: 7 },

sold: 5 sold: 7

output sold : 12

CodePudding user response：

You can use reduce to group and sum the sold property:

const sold = [
  { matri: 1, year: 2019, sold: 5 },
  { matri: 2, year: 2020, sold: 3 },
  { matri: 1, year: 2020, sold: 7 },
];

const result = Object.values(sold.reduce((carry, entry) => {
  if (!carry.hasOwnProperty(entry.matri)) {
     carry[entry.matri] = {matri: entry.matri, sold: entry.sold};
  }
  else {
     carry[entry.matri].sold  = entry.sold;
  }
  return carry;
}, {}));

console.log(result);

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