Javascript - Order array of objects by two date properties

Question

I have an array that contains two different kinds of objects, each with their own date field in which the key is different. See below:

const array = [
  { id: 1, occurs_at: '2017-02-03T07:00:01.000Z' },
  { id: 2, occurs_at: '2017-02-03T10:00:01.000Z' },
  { id: 3, start: '2017-02-03T04:00:01.000Z' },
  { id: 4, start: '2017-02-03T06:00:01.000Z' },
];

I'm trying to get them in ascending order, but I can't seem to find the solution. I've been using Lodash for other sorting based on a single property. Any thoughts?

Is there a way to know which key it'll be? Are there more than two different date keys? Or are 'occurs_at' and 'start' the only two possible date keys? Do the objects have more keys apart from the date and the id? — Shilly
– Shilly, Commented Feb 28, 2017 at 15:24
start and occurs_at are the only possible keys for the date? — baao
– baao, Commented Feb 28, 2017 at 15:24
Edit additional details into your question. Comments are for us to ask for clarifications. — Emile Bergeron
– Emile Bergeron, Commented Feb 28, 2017 at 15:24

Nina Scholz · Accepted Answer · 2017-02-28 15:24:39Z

5

You could test for the wanted property and use only ones with a truthy value.

var array = [{ id: 1, occurs_at: '2017-02-03T07:00:01.000Z' }, { id: 2, occurs_at: '2017-02-03T10:00:01.000Z' }, { id: 3, start: '2017-02-03T04:00:01.000Z' }, { id: 4, start: '2017-02-03T06:00:01.000Z' }];

array.sort(function (a, b) {
    return (a.occurs_at || a.start).localeCompare(b.occurs_at || b.start);
});

console.log(array);

.as-console-wrapper { max-height: 100% !important; top: 0; }

answered Feb 28, 2017 at 15:24

Nina Scholz

388k26 gold badges367 silver badges417 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Adam Boduch · Accepted Answer · 2017-03-01 17:34:55Z

0

I would use sortBy() and pick():

const sorted = _.sortBy(array, i => new Date(
  _(i)
    .pick(['occurs_at', 'start'])
    .values()
    .first()
));

If you know that the each collection item is going to have either an occurs_at or a start property that's a date string, you can use pick() to get both. Obviously only one exists, so this will return an object with the correct value.

At this point, you no longer care about the key, since you know that its an object with a single date value. So you get it using values() and first().

answered Mar 1, 2017 at 17:34

Adam Boduch

11.2k3 gold badges32 silver badges38 bronze badges

Comments

Áron Stankovics · Accepted Answer · 2017-02-28 15:25:32Z

-3

array.sort(function(a, b) {
    return new Date(b.occurs_at) - new Date(a.occurs_at);
});

answered Feb 28, 2017 at 15:25

Áron Stankovics

954 bronze badges

Collectives™ on Stack Overflow

Javascript - Order array of objects by two date properties

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related