indexBy

indexBy(target, by, transform?)

Creates a record by indexing the target array using the by function to generate keys. Optionally transforms values using the transform function.

data-first

const users = [
    { id: 1, name: "Alice" },
    { id: 2, name: "Bob" },
];

indexBy(users, (user) => user.id);
// { 1: { id: 1, name: 'Alice' }, 2: { id: 2, name: 'Bob' } }

indexBy(
    users,
    (user) => user.id,
    (user) => user.name,
); // { 1: "Alice", 2: "Bob" }

data-last

pipe(
    users,
    indexBy((user) => user.id),
); // { 1: { id: 1, name: 'Alice' }, 2: { id: 2, name: 'Bob' } }

pipe(
    users,
    indexBy(
        (user) => user.id,
        (user) => user.name,
    ),
); // { 1: "Alice", 2: "Bob" }