Array with object sorting with Underscore sortBy

Question

I have this array. How do I use underscore '_.sortBy' to sort it according to start date?

[
    { 
        id: 'oljw832021kjnb389xzll323jk',
        start: { dateTime: '2013-09-26T13:30:00-07:00' },
        end: { dateTime: '2013-09-26T14:30:00-07:00' },
    },
    { 
        id: 'ed7l5tmckdp0lm90nvr4is3d4c',
        start: { dateTime: '2013-09-26T15:30:00-07:00' },
        end: { dateTime: '2013-09-26T16:30:00-07:00' },
    },
    { 
        id: 'etmasdsackdp0kjl0nvrkopioqw',
        start: { dateTime: '2013-09-26T18:00:00-07:00' },
        end: { dateTime: '2013-09-26T19:00:00-07:00' },
    }
]

score 169 · Accepted Answer · answered Sep 30 '13 at 09:24

169

Use an iterator function, not a single string for a property:

_.sortBy(arr, function(o) { return o.start.dateTime; })

answered Sep 30 '13 at 09:24

Bergi

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1,375

it gives in ascending order, but how to sort it descending order of date ? – Robin Jan 02 '14 at 14:55
7

@RobinAT: You simply could negate the datetime – Bergi Jan 02 '14 at 23:53
16

if you want to do descending order, then just do arr.reverse() – JrBriones Jan 07 '14 at 21:19
12

if you want descending order of date then use below `_.sortBy(arr, function(o) { var dt = new Date(o.start.dateTime); return -dt; })` – imdadhusen Dec 16 '14 at 11:04
4

@imdadhusen: Yes, that's what I meant when I said "*negate the datetime*". However, that `Date` object is superfluous, you can just do `return -o.start.dateTime;` – Bergi Dec 16 '14 at 14:51
I was looking for a way to sort by `id` (not nested). For this `_sortBy('id')` is enough. Thanks! – Mr. B. Nov 07 '16 at 07:31
Lodash `_.orderBy` is meant for descending order. https://lodash.com/docs/#orderBy – Tuupertunut Mar 27 '17 at 14:36

score 2 · Answer 2 · answered Nov 24 '15 at 17:53

I did it this way:

var sorted = _(list).sortBy(
                    function (item) {                        
                        return [new Date(item.effectiveDate).getTime(), item.batchId];
                    }), "batchId");

If you want it descending then it's the same thing but *-1

var sorted = _(list).sortBy(
                    function (item) {                        
                        return [new Date(item.effectiveDate).getTime()*-1, item.batchId];
                    }), "batchId");

In this example I am ordering by two fields, you can forget about the item.batchId.

Hope this helps someone.

score 1 · Answer 3 · answered Jan 09 '20 at 04:48

1

var sortedItem = _.sortBy(yourArrayName, ["start"])

answered Jan 09 '20 at 04:48

inshu choudhary

11
1

Array with object sorting with Underscore sortBy

3 Answers3

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