std/collections/pick.ts

33 lines
943 B
TypeScript

// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
// This module is browser compatible.
/**
* Creates a new object by including the specified keys from the provided
* object.
*
* @typeParam T The type of the object.
* @typeParam K The type of the keys.
*
* @param obj The object to pick keys from.
* @param keys The keys to include in the new object.
*
* @returns A new object with the specified keys from the provided object.
*
* @example Basic usage
* ```ts
* import { pick } from "@std/collections/pick";
* import { assertEquals } from "@std/assert/assert-equals";
*
* const obj = { a: 5, b: 6, c: 7, d: 8 };
* const picked = pick(obj, ["a", "c"]);
*
* assertEquals(picked, { a: 5, c: 7 });
* ```
*/
export function pick<T extends object, K extends keyof T>(
obj: Readonly<T>,
keys: readonly K[],
): Pick<T, K> {
return Object.fromEntries(keys.map((k) => [k, obj[k]])) as Pick<T, K>;
}