mapValues (Lodash compatibility)

Use mapValues from es-toolkit

This mapValues function is relatively slow due to handling null or undefined and the iteratee conversion process.

Use the faster and more modern mapValues from es-toolkit instead.

Creates a new object by transforming values while keeping keys the same.

const result = mapValues(obj, iteratee);

Reference

mapValues(object, iteratee)

Transforms each value in an object using the iteratee function to create a new object. Keys remain unchanged while only values are modified. Can handle strings, arrays, and objects. Useful for transforming or calculating data.

import { mapValues } from 'es-toolkit/compat';

// Transform object values
const obj = { a: 1, b: 2, c: 3 };
const doubled = mapValues(obj, value => value * 2);
// Result: { a: 2, b: 4, c: 6 }

// Convert strings to uppercase
const names = { first: 'john', last: 'doe' };
const uppercased = mapValues(names, value => value.toUpperCase());
// Result: { first: 'JOHN', last: 'DOE' }

// Transform each character in a string
const str = 'abc';
const charMap = mapValues(str, char => char.toUpperCase());
// Result: { '0': 'A', '1': 'B', '2': 'C' }

// Convert array to object
const arr = [10, 20, 30];
const arrMap = mapValues(arr, (value, index) => value + index);
// Result: { '0': 10, '1': 21, '2': 32 }

// Extract values using property path
const users = {
  user1: { profile: { name: 'Alice' } },
  user2: { profile: { name: 'Bob' } },
};
const userNames = mapValues(users, 'profile.name');
// Result: { user1: 'Alice', user2: 'Bob' }

null or undefined are treated as empty objects.

import { mapValues } from 'es-toolkit/compat';

mapValues(null, iteratee); // {}
mapValues(undefined, iteratee); // {}

Parameters

• object (string | T[] | T | null | undefined): The object, array, or string to transform values from.
• iteratee (ValueIteratee<any>, optional): The function, property path, or matching object to transform each value. Defaults to the identity function.

Returns

(Record<number, T> | { [P in keyof T]: U } | Record<string, boolean> | Record<string, any> | Partial<T>): Returns a new object with transformed values.