I need to find the elements with the same id in the array below, add their amounts and write them in a single line.
let arr = [
{ itemId: 123, name: '0', quantity: 2 },
{ itemId: 1, name: '1', quantity: 2 },
{ itemId: 13, name: '2', quantity: 2 },
{ itemId: 13, name: '3', quantity: 2 },
{ itemId: 13, name: '4', quantity: 24 },
{ itemId: 13, name: '5', quantity: 2 },
{ itemId: 1, name: '6', quantity: 4 },
{ itemId: 1, name: '7', quantity: 2 },];
I want an output like this:
[{ itemId: 123, name: '1', quantity: 2 },
{ itemId: 1, name: '2', quantity: 6 },
{ itemId: 13, name: '6', quantity: 30 }];
And my code:
const getPureList = () => {
for (let index = 0; index < arr.length; index++) {
for (let a = index + 1; a < arr.length; a++) {
if (arr[index].itemId === arr[a].itemId) {
arr[index].quantity += arr[a].quantity;
arr.splice(a, 1);
}
}
}
return arr;
};
Thanks for your help.
By keeping the name od the first object of the group, you could take an object for grouping and take the values as result.
const
array = [{ itemId: 123, name: '0', quantity: 2 }, { itemId: 1, name: '1', quantity: 2 }, { itemId: 13, name: '2', quantity: 2 }, { itemId: 13, name: '3', quantity: 2 }, { itemId: 13, name: '4', quantity: 24 }, { itemId: 13, name: '5', quantity: 2 }, { itemId: 1, name: '6', quantity: 4 }, { itemId: 1, name: '7', quantity: 2 }],
result = Object.values(array.reduce((r, o) => {
r[o.itemId] ??= { ...o, quantity: 0 };
r[o.itemId].quantity += o.quantity;
return r;
}, {}));
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }