Sort array of objects with date field by date
JavascriptSortingDateLodashJavascript Problem Overview
Give the following array of objects, I need to sort them by the date field ascending.
var myArray = [
{
name: "Joe Blow",
date: "Mon Oct 31 2016 00:00:00 GMT-0700 (PDT)"
},
{
name: "Sam Snead",
date: "Sun Oct 30 2016 00:00:00 GMT-0700 (PDT)"
},
{
name: "John Smith",
date: "Sat Oct 29 2016 00:00:00 GMT-0700 (PDT)"
}
];
so that in this example, the final result would be John Smith, Sam Snead, and Joe Blow.
I am trying to use lodash's _.sortBy(), but I can't get any sorting to take place no matter how I try to use it:
_.sortBy(myArray, function(dateObj) {
return dateObj.date;
});
or
_.sortBy(myArray, 'date');
What do I need to change to get my array sorted properly? I also have Moment.js, so I can use it to format the date string if needed. I tried converting the date property using .unix(), but that didn't make a difference.
Thanks.
Javascript Solutions
Solution 1 - Javascript
You don't really need lodash. You can use JavaScript's Array.prototype.sort
method.
You'll need to create Date
objects from your date strings before you can compare them.
var myArray = [{
name: "Joe Blow",
date: "Mon Oct 31 2016 00:00:00 GMT-0700 (PDT)"
}, {
name: "Sam Snead",
date: "Sun Oct 30 2016 00:00:00 GMT-0700 (PDT)"
}, {
name: "John Smith",
date: "Sat Oct 29 2016 00:00:00 GMT-0700 (PDT)"
}];
myArray.sort(function compare(a, b) {
var dateA = new Date(a.date);
var dateB = new Date(b.date);
return dateA - dateB;
});
console.log(myArray);
Solution 2 - Javascript
Your date values are strings, so you need to use the new Date()
constructor to change them to javascript date
objects. This way you can sort them (using _.sortBy
).
var myArray = [
{
name: "Joe Blow",
date: "Mon Oct 31 2016 00:00:00 GMT-0700 (PDT)"
},
{
name: "Sam Snead",
date: "Sun Oct 30 2016 00:00:00 GMT-0700 (PDT)"
},
{
name: "John Smith",
date: "Sat Oct 29 2016 00:00:00 GMT-0700 (PDT)"
}
];
myArray = _.sortBy(myArray, function(dateObj) {
return new Date(dateObj.date);
});
console.log(myArray)
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.2/lodash.min.js"></script>
Solution 3 - Javascript
Here's a solution using standard Javascript by converting both values to date object and comparing their value.
myArray.sort((d1, d2) => new Date(d1.date).getTime() - new Date(d2.date).getTime());
A complete snippet:
var myArray = [ { name: "Joe Blow", date: "Mon Oct 31 2016 00:00:00 GMT-0700 (PDT)" }, { name: "Sam Snead", date: "Sun Oct 30 2016 00:00:00 GMT-0700 (PDT)" }, { name: "John Smith", date: "Sat Oct 29 2016 00:00:00 GMT-0700 (PDT)" }];
myArray.sort((d1, d2) => new Date(d1.date).getTime() - new Date(d2.date).getTime());
console.log(myArray);
Solution 4 - Javascript
If you are trying to use lodash to sort dates in ascending or descending order for your array of objects, you should use _.orderBy
instead of _.sortBy
https://lodash.com/docs/4.17.15#orderBy, this method allows specifying sort orders either by 'asc' or 'desc'
An example would be:
const sortedArray = _(myArray.orderBy([
function(object) {
return new Date(object.date);
}],["desc"])
Solution 5 - Javascript
just write _.sortBy({yourCollection}, {the field name});
lodash will automatically figure that this is a date and it'll work like a magic!
Awesome!
Solution 6 - Javascript
A cleaner way using Lodash orderBy:
import _ from 'lodash'
const sortedArray = _.orderBy(myArray, [(obj) => new Date(obj.date)], ['asc'])
Solution 7 - Javascript
Inspired by others answers and noticing that you used moment.js and lodash, you can combine both with _.orderBy
lodash method:
import moment from 'moment'
import * as _ from 'lodash'
let myArray = [
{
name: "Joe Blow",
date: "Mon Oct 31 2016 00:00:00 GMT-0700 (PDT)"
},
{
name: "Sam Snead",
date: "Sun Oct 30 2016 00:00:00 GMT-0700 (PDT)"
},
{
name: "John Smith",
date: "Sat Oct 29 2016 00:00:00 GMT-0700 (PDT)"
}
];
myArray = _.orderBy(myArray, [(item) => {
return moment(item.date).format('YYYY-MM-DD')
}], ['desc'])