I have an array:
const arr = [
{ name: "Jeff", id: 1 },
{ name: "Mary", id: 2 },
{ name: "Jeff", id: 3 },
{ name: "Mary", id: 4 },
{ name: "Emile", id: 5 },
];
I want to turn it into this:
const obj = {
Jeff: [1, 3],
Mary: [2, 4],
Emile: [5],
};
I tried using the Array.reduce method, but I can't seem to wrap my head around the logic.
const obj = arr.reduce((acc, info) => {
acc[info[name]] = ....
return acc;
}, {});
I assume it can be done with the reduce method
You are on the right track, you just need to check to see if the array is there.
const arr = [
{ name: "Jeff", id: 1 },
{ name: "Mary", id: 2 },
{ name: "Jeff", id: 3 },
{ name: "Mary", id: 4 },
{ name: "Emile", id: 5 },
];
const result = arr.reduce((acc, { name, id }) => {
acc[name] = acc[name] || []; // or if(!acc[name]) acc[name] = [];
acc[name].push(id);
return acc;
}, {});
console.log(result);You can do like this:
const arr = [
{ name: "Jeff", id: 1 },
{ name: "Mary", id: 2 },
{ name: "Jeff", id: 3 },
{ name: "Mary", id: 4 },
{ name: "Emile", id: 5 },
];
const result = arr.reduce(
(acc, cur) => ((acc[cur.name] || (acc[cur.name] = [])).push(cur.id), acc),
{}
);
console.log(result);