I would like to filter on a particular object property. If that property is false OR undefined/null, I want it included. In the example below, I am summing by the deliciousRating as long as isBruised is not true. However, I can't figure out how to include the undefined/null value.
var apples = [
{isBruised: true, deliciousRating: 1},
{isBruised: false, deliciousRating: 10},
{deliciousRating: 9}
];
_.sumBy(_.filter(apples, ['isBruised', false]), 'deliciousRating');
I would like this to return 19, but currently it is only getting the deliciousRating from apples[1].
Use _.reject()
instead of _.filter()
. The _.reject()
method is...
The opposite of _.filter; this method returns the elements of collection that predicate does not return truthy for.
var apples = [
{isBruised: true, deliciousRating: 1},
{isBruised: false, deliciousRating: 10},
{deliciousRating: 9}
];
var result = _.sumBy(_.reject(apples, 'isBruised'), 'deliciousRating');
console.log(result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>
And in vanilla JS, you can use Array#reduce to sum just the items that are not bruised:
var apples = [
{isBruised: true, deliciousRating: 1},
{isBruised: false, deliciousRating: 10},
{deliciousRating: 9}
];
var result = apples.reduce(function(s, o) {
return o.isBruised ? s : s + o.deliciousRating;
}, 0);
console.log(result);