const myObject = [
{
"date": "2023-01-01",
"time": "18:00",
"somevalue": 2
},
{
"date": "2023-01-01",
"time": "18:00",
"somevalue": 5
},
{
"date": "2023-01-02",
"time": "19:00",
"somevalue": 10
},
{
"date": "2023-01-03",
"time": "06:00",
"somevalue": 13
}
];
const all = myObject.reduce( (prev, value) => (
{ ...prev, [value.date]: (prev[value.date] || 0) + value.somevalue } ), {});
// to array
console.log(
Object.entries(all).map( ([key, value]) => ( {date: key, somevalue: value} ) )
);My question is: How can I add the "time" value. Like this:
[
{
"date": "2023-01-01",
"time": "18:00",
"somevalue": 7
},
{
"date": "2023-01-02",
"time": "19:00",
"somevalue": 10
},
{
"date": "2023-01-03",
"time": "06:00",
"somevalue": 13
}
]
Maybe something like this?
const myObject = [ { date: "2023-01-01", time: "18:00", somevalue: 2 }, { date: "2023-01-01", time: "18:00", somevalue: 5 }, { date: "2023-01-02", time: "19:00", somevalue: 10 }, { date: "2023-01-03", time: "06:00", somevalue: 13 }];
const output = myObject.reduce((arr, acc) => {
const index = arr.findIndex(({ date, time }) => date === acc.date && time === acc.time); //find duplicated elements by date
if (index > -1) { // if you have duplicated element
arr[index] = {
...arr[index], // merge objects
somevalue: arr[index].somevalue + acc.somevalue // add value
};
} else {
arr = [...arr, acc]; //if no duplicates values, just add to array.
}
return arr;
}, []);
console.log(output)I use reduce to merge duplicated elements by "date" and add the someValue.
This would also work
const myObject = [ { date: "2023-01-01", time: "18:00", somevalue: 2, }, { date: "2023-01-01", time: "18:00", somevalue: 5, }, { date: "2023-01-02", time: "19:00", somevalue: 10, }, { date: "2023-01-03", time: "06:00", somevalue: 13, }, ];
const output = Object.entries(
myObject.reduce((prev, { date, time, somevalue }) => {
// create a key like <date>$<time> and add up
// somevalue when key is discovered again
prev[`${date}$${time}`] =
prev[`${date}$${time}`] != undefined
? prev[`${date}$${time}`] + somevalue
: somevalue;
return prev;
}, {})
).map(([key, somevalue]) => {
// split the key using $ and get date and time
// return created object
const [date, time] = key.split("$");
return { date, time, somevalue };
});
console.log(output);