What is the best way to convert to following array. Do I need to map over it or is there some other way with Object.values etc:
[
{
key: "eyeColor",
value: "Blue/Green",
},
{
key: "eyeColor",
value: "Blue",
},
{
key: "hairColor",
value: "black",
}
];
into:
{
hairColor: ["Blond", "Brown"],
eyeColor: ["Blue"],
}
Array#reduce, iterate over the array while updating a Map where the key is the key properties and the value is the corresponding grouped-value properties.Array#map, iterate over the above pairs and convert to objects:const data = [ { key: "eyeColor", value: "Blue/Green" }, { key: "eyeColor", value: "Blue" }, { key: "hairColor", value: "black" } ];
const groupedPairs = [...data.reduce((map, { key, value }) => map.set(key, [...(map.get(key) ?? []), value]), new Map)];
const list = groupedPairs.map(([ prop, list ]) => ({ [prop]: list }))
console.log(list);EDIT AFTER CHANGE OF EXPECTED OUTPUT:
const data = [ { key: "eyeColor", value: "Blue/Green" }, { key: "eyeColor", value: "Blue" }, { key: "hairColor", value: "black" } ];
const res = data.reduce((acc, { key, value }) => ({
...acc, [key]: [...(acc[key] ?? []), value]
}), {});
console.log(res);