unionBy
Creates an array of unique values, in order, from all given arrays using a provided mapping function to determine equality.
Signature
typescript
function unionBy<T, U>(arr1: T[], arr2: T[], mapper: (item: T) => U): T[];Parameters
arr1(T[]): The first array.arr2(U[]): The second array.mapper: ((item: T) => U): The function to map array elements to comparison values.
Returns
(T[]): A new array containing the union of unique elements from arr1 and arr2, based on the values returned by the mapping function.
Examples
typescript
unionBy([{ id: 1 }, { id: 2 }], [{ id: 2 }, { id: 3 }], x => x.id);
// Returns [{ id: 1 }, { id: 2 }, { id: 3 }]