_.unionWith

_.unionWith([arrays], [comparator])

This method is like _.union except that it accepts comparator which is invoked to compare elements of arrays. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).

Since

4.0.0

Arguments

1. [arrays] (...Array): The arrays to inspect.
2. [comparator] (Function): The comparator invoked per element.

Returns

(Array): Returns the new array of combined values.

Example

var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];

var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];
 
_.unionWith(objects, others, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]