find similar value of an array object and calculate the sold

December 7, 2021

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

>Solution :

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);