unionBy source npm
_.unionBy([arrays], [iteratee=_.identity])
This method is like _.union
except that it accepts iteratee
which is
invoked for each element of each arrays
to generate the criterion by which
uniqueness is computed. The iteratee is invoked with one argument: (value).
Arguments
- [arrays] (...Array)
The arrays to inspect.
- [iteratee=_.identity] (Function|Object|string)
The function invoked per element.
Returns (Array)
Returns the new array of combined values.
Example
_.unionBy([2.1, 1.2], [4.3, 2.4], Math.floor);
// => [2.1, 1.2, 4.3]
// using the `_.property` callback shorthand
_.unionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]