4.17.11
3.10.1
2.4.2
1.3.1

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

sourcenpm package

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

argument
[arrays]
[comparator]
type
...Array
Function
description
The arrays to inspect.
The comparator invoked per element.

Returns

(array)

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 }]

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 }]