Get unique objects if theres an array which is repeated in some other object in an array of objects

Question

const messages = [{ id: 1, name: "Jack", users: [2,4] }, { id: 2, name: "Alex", users: [2,6] }, { id: 3, name: "John", users: [2,6] }]

Need to get unique object based on a nested array key. check if array containing same value is repeated in some other object and return only the last record which has the nested duplicate

expected answer =

[{ id: 1, name: "Jack", users: [2,4]},{id: 3, name: "John", users: [2,6] }]

Answer 1

You could use a combined key of users with an object and get unique items.

const
    messages = [{ id: 1, name: "Jack", users: [2, 4] }, { id: 2, name: "Alex", users: [2, 6] }, { id: 3, name: "John", users: [2, 6] }],
    result = Object.values(messages.reduce((r, o) => {
        r[o.users.join('|')] = o;
        return r;
    }, {}));

console.log(result);

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