I have some data that needs to be transformed into one array, one by one.
This is the example data (there can be a lot more squads):
var my_arr = [];
var squad1 = [
{ date: "2022-04-04", number_of_checkable_cells: 2 },
{ date: "2022-04-05", number_of_checkable_cells: 2 }
];
var squad2 = [
{ date: "2022-04-04", number_of_checkable_cells: 2 },
{ date: "2022-04-05", number_of_checkable_cells: 1 },
{ date: "2022-04-06", number_of_checkable_cells: 2 }
];
What happens: my_arr receives squad1 to add it, later squad2 joins the party.
So after squad1 is added my_arr should be:
my_arr = [
{ date: "2022-04-04", number_of_checkable_cells: 2 },
{ date: "2022-04-05", number_of_checkable_cells: 2 }
];
Then the data of squad2 is received and I want the following result:
my_arr = [
{ date: '2022-04-04', number_of_checkable_cells: 4 },
{ date: '2022-04-05', number_of_checkable_cells: 3 },
{ date: '2022-04-06', number_of_checkable_cells: 2 }
]
The code that I have:
function reduce_it(arr) {
return arr.reduce((initiator, curr) => {
var obj = initiator.find((i) => i.date == curr.date);
if (obj) obj.number_of_checkable_cells += curr.number_of_checkable_cells;
else initiator.push(curr);
return initiator;
}, []);
}
my_arr = [...my_arr, ...squad1];
my_arr = reduce_it(my_arr);
my_arr = [...my_arr, ...squad2];
my_arr = reduce_it(my_arr);
Is there a better way to get to the same result? If there is, please guide me. :)
I would keep the target array and mutate it.
function add(target, source) {
return source.reduce((t, o) => {
const item = t.find(({ date }) => date == o.date);
if (item) item.number_of_checkable_cells += o.number_of_checkable_cells;
else t.push({ ...o });
return t;
}, target);
}
const
squad1 = [{ date: "2022-04-04", number_of_checkable_cells: 2 }, { date: "2022-04-05", number_of_checkable_cells: 2 }],
squad2 = [{ date: "2022-04-04", number_of_checkable_cells: 2 }, { date: "2022-04-05", number_of_checkable_cells: 1 }, { date: "2022-04-06", number_of_checkable_cells: 2 }],
my_arr = [];
add(my_arr, squad1);
console.log(my_arr);
add(my_arr, squad2);
console.log(my_arr);What you suggest works, but here is what I suggest you to do. Basically, each time a new squad arrive you can loop through it and update your array of squad as follow:
var my_arr = [];
var squad1 = [
{ date: "2022-04-04", number_of_checkable_cells: 2 },
{ date: "2022-04-05", number_of_checkable_cells: 2 }
];
my_arr.push(...squad1);
// Here you received the squad 2
var squad2 = [
{ date: "2022-04-04", number_of_checkable_cells: 2 },
{ date: "2022-04-05", number_of_checkable_cells: 1 },
{ date: "2022-04-06", number_of_checkable_cells: 2 }
];
for (const squad of squad2) {
const existingSquad = my_arr.find(
(prevSquad) => prevSquad.date === squad.date
);
if (existingSquad) {
existingSquad.number_of_checkable_cells +=
squad.number_of_checkable_cells;
} else {
my_arr.push(squad);
}
}
console.log(my_arr);
/*
(3) [{…}, {…}, {…}]
0: {date: '2022-04-04', number_of_checkable_cells: 4}
1: {date: '2022-04-05', number_of_checkable_cells: 3}
2: {date: '2022-04-06', number_of_checkable_cells: 2}
length: 3
*/
So this example is the raw one, if you want to wrap it in a method look below:
function updateSquads(squads, newSquads) {
for (const squad of newSquads) {
const existingSquad = squads.find(
(prevSquad) => prevSquad.date === squad.date
);
if (existingSquad) {
existingSquad.number_of_checkable_cells +=
squad.number_of_checkable_cells;
} else {
squads.push(squad);
}
}
}
var my_arr = [];
var squad1 = [
{ date: "2022-04-04", number_of_checkable_cells: 2 },
{ date: "2022-04-05", number_of_checkable_cells: 2 }
];
my_arr.push(...squad1);
// Here you receive squad 2
var squad2 = [
{ date: "2022-04-04", number_of_checkable_cells: 2 },
{ date: "2022-04-05", number_of_checkable_cells: 1 },
{ date: "2022-04-06", number_of_checkable_cells: 2 }
];
updateSquads(my_arr, squad2)
console.log(my_arr);
/*
(3) [{…}, {…}, {…}]
0: {date: '2022-04-04', number_of_checkable_cells: 4}
1: {date: '2022-04-05', number_of_checkable_cells: 3}
2: {date: '2022-04-06', number_of_checkable_cells: 2}
length: 3
*/