Intersects

Check if two lists intersect.

🎬 Usage

<script>
    import {intersects} from "@sveu/shared/lists"

    const a = [1, 2, 3]

    const b = [2, 3, 4]

    const [intersects, intersecting] = intersects(a, b) // [true, [2, 3]]
</script>

👩‍💻API

👻 Arguments

Name	Description	Type	Required
a	First list	`T[]`	Yes
b	Second list	`T[]`	Yes

🙈 Options

Name	Description	Type	Default
fn	A function that returns a unique key for each item in the array.	`fn?: (item: T) => K`	`item => item`

↩️ Returns

A tuple of the items that intersect and boolean indicating if the lists intersect.

🧪 Playground

Source Code 👀

Source Code

import type { IntersectsOptions } from "../../utils"

/**
 * Determine whether the given arrays intersect.
 *
 * @param a - The first array.
 *
 * @param b - The second array.
 *
 * @param options - options:
 * - `fn` - A function that returns a unique key for each item in the array.
 *
 * @returns a boolean value indicating whether the arrays intersect and the intersecting items.
 */
export function intersects<T, K extends string | number | symbol>(
    a: T[],
    b: T[],
    options: IntersectsOptions<T, K> = {}
): [boolean, T[]] {
    const { fn = (item: T) => item as unknown as K } = options

    if (!a || !b) return [false, []]

    const dict_b = b.reduce(
        (acc, item) => ({ ...acc, [fn(item)]: true }),
        {} as Record<K, boolean>
    )

    return [
        a.some((item) => dict_b[fn(item)]),
        a.filter((item) => dict_b[fn(item)]),
    ]
}

Last update: 2023-02-14

Authors: Mohamed-Kaizen