Lodash/Underscore : Check for a value within an array, in an array of objects

Question

Confusing title, the only simple way to explain is to show you what I'm after :

var user = [
  {foo:"test",bar:1},
  {foo:"test2",bar:2}
];

var items = [{foo:"test",bar:1},{foo:"test4",bar:4},{foo:"test5",bar:5}]

What I want, is to pick one item from items which is not already in user, and add it to user. In this case the user object would end up looking like :

user = [
  {foo:"test",bar:1},
  {foo:"test2",bar:2},
  {foo:"test4",bar:4}
];

I've tried all sorts of _.filter, _.contains, etc... combinations, but can't quite figure it out. Any help would be very appreciated!

cus that would be selfish if one user would take all the items ;) could be one or the other though, it makes no difference. — xShirase
– xShirase, Commented Dec 1, 2014 at 23:30

GregL · Accepted Answer · 2014-12-01 23:43:25Z

1

The logic is as follows: you want to find the first item that is not contained within the user array.

So you can do the following:

var item = _.find(items, function (item) {
    return !_.findWhere(user, item);
});

jsFiddle Demo

answered Dec 1, 2014 at 23:43

GregL

38.2k8 gold badges65 silver badges68 bronze badges

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

1 Comment

xShirase Over a year ago

Wow, that's pretty, I was already starting to write an ugly for loop to do the job. Thanks!

Collectives™ on Stack Overflow

Lodash/Underscore : Check for a value within an array, in an array of objects

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related