I have the following array:
let array = [
{ date: '2022-06-29', cost: 3.874886 },
{ date: '2022-06-28', cost: 3.357631 },
{ date: '2022-06-28', cost: 92.24 },
{ date: '2022-06-28', cost: 221.47 },
{ date: '2022-06-28', cost: 164.8 },
{ date: '2022-06-29', cost: 263.58 },
{ date: '2022-06-29', cost: 30.19 },
{ date: '2022-06-29', cost: 3.72 },
{ date: '2022-11-29', cost: 33.19 },
{ date: '2022-11-01', cost: 31.72 }
]
I'm trying to use the .reduce method to get the sum of cost, grouped by date, which would look like this:
[
{date: '2022-06-28', cost: 481.867631},
{date: '2022-06-28', cost: 301.364886},
{date: '2022-11-01', cost: 31.72},
{date: '2022-11-29', cost: 33.19}
]
you can do something like this
const group = data => Object.values(data.reduce((res, {date, cost}) => {
return {
...res,
[date]: {date, cost: (res[date] || {cost:0}).cost + cost}
}
}, {}))
const data = [
{ date: '2022-06-29', cost: 3.874886 },
{ date: '2022-06-28', cost: 3.357631 },
{ date: '2022-06-28', cost: 92.24 },
{ date: '2022-06-28', cost: 221.47 },
{ date: '2022-06-28', cost: 164.8 },
{ date: '2022-06-29', cost: 263.58 },
{ date: '2022-06-29', cost: 30.19 },
{ date: '2022-06-29', cost: 3.72 },
{ date: '2022-11-29', cost: 33.19 },
{ date: '2022-11-01', cost: 31.72 }
]
console.log(group(data))let array = [
{ date: '2022-06-29', cost: 3.874886 },
{ date: '2022-06-28', cost: 3.357631 },
{ date: '2022-06-28', cost: 92.24 },
{ date: '2022-06-28', cost: 221.47 },
{ date: '2022-06-28', cost: 164.8 },
{ date: '2022-06-29', cost: 263.58 },
{ date: '2022-06-29', cost: 30.19 },
{ date: '2022-06-29', cost: 3.72 },
{ date: '2022-11-29', cost: 33.19 },
{ date: '2022-11-01', cost: 31.72 }
]
const result = array.reduce((acc, item) => {
const itemIndex = acc.findIndex(i => i.date === item.date);
if (itemIndex !== -1) {
acc[itemIndex].cost += item.cost
} else {
acc.push(item)
}
return acc;
}, [])
console.log(result)[
{date: '2022-06-28', cost: 481.867631},
{date: '2022-06-28', cost: 301.364886},
{date: '2022-11-01', cost: 31.72},
{date: '2022-11-29', cost: 33.19}
]here is my way to achieve your desire output.
let array = [
{ date: '2022-06-29', cost: 3.874886 },
{ date: '2022-06-28', cost: 3.357631 },
{ date: '2022-06-28', cost: 92.24 },
{ date: '2022-06-28', cost: 221.47 },
{ date: '2022-06-28', cost: 164.8 },
{ date: '2022-06-29', cost: 263.58 },
{ date: '2022-06-29', cost: 30.19 },
{ date: '2022-06-29', cost: 3.72 },
{ date: '2022-11-29', cost: 33.19 },
{ date: '2022-11-01', cost: 31.72 }
]
const newArray = array.reduce((prev, curr) => {
const check = prev.findIndex(f => f.date === curr.date);
if (check > -1) {
prev[check].cost += curr.cost
} else {
prev.push(curr)
}
return prev;
}, []);
console.log(newArray)