Sorting of array of object with multiple key values

Question

const users = [
  { 'user': 'fred' },
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 40 },
  { 'user': 'barney', 'age': 34 },
  { 'user': 'arney', 'age': 36 },
  { 'user': 'ared' },
];

---------------Expected output-----------

const sortedArray = [ {age: 34, user: "barney"}, 
                      {age: 36, user: "arney"},
                      {age: 36, user: "barney"},
                      {age: 40, user: "fred"},
                      {user: "ared"},
                      {user: "fred"},
                     ];

It should sort by age!
If age is equal then sort on the basis of the user key.
If the age key is not available it should insert those objects at last.

users.sort((a, b) => { if (a.age || b.age) { return a.age - b.age; } return a.user > b.user ? 1 : -1; }); — Shubham, Nov 02 '20 at 18:32

score 2 · Accepted Answer · answered Nov 02 '20 at 18:35

2

You could take a default value of Number.MAX_VALUE for calculating the delta of age.

const users = [{ user: 'fred' }, { user: 'barney', age: 36 }, { user: 'fred', age: 40 }, { user: 'barney', age: 34 }, { user: 'arney', age: 36 }, { user: 'ared' }];

users.sort((a, b) =>
    (a.age ?? Number.MAX_VALUE) - (b.age ?? Number.MAX_VALUE) ||
    a.user.localeCompare(b.user)
);

console.log(users);

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answered Nov 02 '20 at 18:35

Nina Scholz

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that is some cool syntax. How is the `??`-operator called? – DivisionByZero Nov 02 '20 at 18:51
1

[Nullish coalescing operator `??`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_operator) – Nina Scholz Nov 02 '20 at 18:51

score 0 · Answer 2 · answered Nov 02 '20 at 18:35

Simple compare function would do the job. First compare by age, if equal then by user and if age is not available it will put those at last.

const users = [
  { user: 'fred' },
  { user: 'barney', age: 36 },
  { user: 'fred', age: 40 },
  { user: 'barney', age: 34 },
  { user: 'arney', age: 36 },
  { user: 'ared' },
];

const cmp = (x, y) => {
  if (x.age === y.age) {
    return x.user.localeCompare(y.user);
  }
  if (!x.age) {
    return 1;
  }
  if (!y.age) {
    return -1;
  }
  return x.age > y.age ? 1 : -1;
};
const ret = users.sort(cmp);
console.log(ret);

Sorting of array of object with multiple key values

2 Answers2