8ee50178f3
Correct: `Array.from()` (it’s a static method) Incorrect: `Array.join()` (doesn’t exist; it’s a prototype method) This patch uses the common `#` syntax to denote `.prototype.`.
528 B
528 B
mapKeys
Creates an object with keys generated by running the provided function for each key and the same values as the provided object.
Use Object.keys(obj) to iterate over the object's keys.
Use Array.prototype.reduce() to create a new object with the same values and mapped keys using fn.
const mapKeys = (obj, fn) =>
Object.keys(obj).reduce((acc, k) => {
acc[fn(obj[k], k, obj)] = obj[k];
return acc;
}, {});
mapKeys({ a: 1, b: 2 }, (val, key) => key + val); // { a1: 1, b2: 2 }