mapKeys

Creates a new object with the same values as the given object, but with keys generated by running each own enumerable property of the object through the getNewKey function.

Signature

function mapKeys<T extends Record<PropertyKey, unknown>, K1 extends keyof T, K2 extends PropertyKey>(
  object: T,
  getNewKey: (value: T[K1], key: K1, object: T) => N
): Record<K2, T[K]>;

Parameters

• obj (T extends object): The object to iterate over.
• getNewKey: ((value: T[K1], key: K1, object: T) => N): The function invoked per own enumerable property.

Returns

(Record<K2, T[K]>): The new mapped object.

Examples

const obj = { a: 1, b: 2 };
const result = mapKeys(obj, (value, key) => key + value);
console.log(result); // { a1: 1, b2: 2 }

Performance Comparison

	Bundle Size	Performance
es-toolkit	138 bytes (99.1% smaller)	2,844,013 times (11% faster)
es-toolkit/compat	1,124 bytes (93.2% smaller)	2,899,524 times (13% faster)
lodash-es	16,649 bytes	2,559,949 times