intersectionWith (Functional Programming)

Creates a function that keeps values using a custom equality function. Use it with pipe.

const result = pipe(array, intersectionWith(secondArray, areItemsEqual));

::: info

Prefer the original es-toolkit intersectionWith in ordinary code. Use this fp variant when composing transformations with pipe.

:::

Usage

intersectionWith keeps values from the piped array when areItemsEqual returns true for at least one value in secondArray.

import { intersectionWith, pipe } from 'es-toolkit/fp';

pipe(
  [{ id: 1 }, { id: 2 }],
  intersectionWith([{ id: 2 }], (a, b) => a.id === b.id)
); // => [{ id: 2 }]

Parameters

• secondArray (readonly U[]): The array containing values to compare against.
• areItemsEqual ((item: T, other: U) => boolean): The function that decides whether two values are equal.

Returns

((array: readonly T[]) => T[]): A function that maps a readonly T[] to values matched by the comparator.