mapToDictionary()
Run a dictionary map over the items. The callback should return an associative array with a single key/value pair.
const collection = collect([
{ id: 1, name: "a" },
{ id: 2, name: "b" },
{ id: 3, name: "c" },
{ id: 4, name: "b" }
]);
const groups = collection.mapToDictionary(item => [item.name, item.id]);
groups.all();
//=> {
//=> a: [1],
//=> b: [2, 4],
//=> c: [3],
//=> }