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

confusing title, simple way explain show 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 want, pick one item items not in user, , add user. in case user object end looking :

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

i've tried sorts of _.filter, _.contains, etc... combinations, can't quite figure out. appreciated!

the logic follows: want find first item not contained within user array.

so can following:

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

WINAPI