Hi guys i want to do something "simple" but not for me, I have this array
[
{ x: 'bmw', vehicule_type: car, y: 1 },
{ x: 'mercedes', vehicule_type: car, y: 2 },
{ x: 'airbus', vehicule_type: plane, y: 1 }
]
And i want to transform it to this thing
[
car : [{ x: 'bmw', y: 1 }, { x: 'mercedes', y: 1 }]
plane: [{ x: 'airbus', y: 1 }]
]
I cant find a way to do it, i saw that i could use "reducer()" but for the rest i'm lost
Presented below is one possible way to achieve the desired objective.
Code Snippet
const myTransform = arr => (
arr.reduce(
(acc, {vehicule_type, ...rest}) => (
(acc[vehicule_type] ??= []).push({...rest}),
acc
),
{}
)
);
/* EXPLANATION of the code
// method to transform the array
const myTransform = arr => (
arr.reduce( // iterate using ".reduce()" with "acc" as accumulator
// destructure the iterator to acces "vehicule_type"
(acc, {vehicule_type, ...rest}) => (
// if "acc" doesn't have "vehicule_type", set it as empty array
// and then, push "rest" (ie, x, y, other props, if any) into the array
(acc[vehicule_type] ??= []).push({...rest}),
// implicit return of "acc"
acc
),
{} // initialize "acc" as an empty object
)
);
*/
const dataArr = [
{ x: 'bmw', vehicule_type: 'car', y: 1 },
{ x: 'mercedes', vehicule_type: 'car', y: 2 },
{ x: 'airbus', vehicule_type: 'plane', y: 1 }
];
console.log(myTransform(dataArr));.as-console-wrapper { max-height: 100% !important; top: 0 }Explanation
Inline comments added to the snippet above.
EDIT
As noted by Bergi in a comment below, an alternative using for loop is also possible. This may look something as shown below:
const myTransform = arr => {
const res = {};
for (const {vehicule_type, ...rest} of dataArr) {
(res[vehicule_type] ??= []).push({...rest});
};
return res;
};
/* EXPLANATION
// alternative method to transform the array
const myTransform = arr => {
// set up result "res" as an empty object "{}"
const res = {};
// iterate over elts of "dataArr"
// destructure the iterator to directly access "vehicule_type"
for (const {vehicule_type, ...rest} of dataArr) {
// if "vehicule_type" not already in "res",
// then, set it with a value of empty array
// push the remaining props "...rest" into the array
(res[vehicule_type] ??= []).push({...rest});
};
// return the result
return res;
};
*/
const dataArr = [
{ x: 'bmw', vehicule_type: 'car', y: 1 },
{ x: 'mercedes', vehicule_type: 'car', y: 2 },
{ x: 'airbus', vehicule_type: 'plane', y: 1 }
];
console.log(myTransform(dataArr));.as-console-wrapper { max-height: 100% !important; top: 0 }You can group the data by vehicle_type using Array.prototype.reduce.
const
data = [
{ x: "bmw", vehicle_type: "car", y: 1 },
{ x: "mercedes", vehicle_type: "car", y: 2 },
{ x: "airbus", vehicle_type: "plane", y: 1 },
],
result = data.reduce(
(r, { vehicle_type: t, ...o }) => ((r[t] ??= []).push(o), r),
{}
);
console.log(result);If you're finding it difficult to understand the above solution, refer to this more descriptive version:
const
data = [
{ x: "bmw", vehicle_type: "car", y: 1 },
{ x: "mercedes", vehicle_type: "car", y: 2 },
{ x: "airbus", vehicle_type: "plane", y: 1 },
],
result = data.reduce((r, { vehicle_type: t, ...o }) => {
if (!r[t]) {
r[t] = [];
}
r[t].push(o);
return r;
}, {});
console.log(result);Relevant documentations:
I'm not sure whether this is the best way to do this; probably not, but this is what I came up with..
let array = [{
x: 'bmw',
vehicle_type: "car",
y: 1
},
{
x: 'mercedes',
vehicle_type: "car",
y: 2
},
{
x: 'airbus',
vehicle_type: 'plane',
y: 1
},
{
x: 'mercedes',
vehicle_type: "car",
y: 2
}
]
function sortByType(array) {
const vehicles = {};
for (let object of array) {
let vehicle = {},
type = undefined;
for (let property in object) {
if (type === undefined) type = object["vehicle_type"];
if (vehicles[type] === undefined) vehicles[type] = [];
if (property === "vehicle_type") continue;
vehicle[property] = object[property];
}
vehicles[type].push(vehicle);
}
return vehicles
}
const vehicles = sortByType(array)
console.log(vehicles)