45 lines
1.9 KiB
JavaScript
45 lines
1.9 KiB
JavaScript
|
import { identity } from "../../function/identity.mjs";
|
||
|
|
import { isArrayLike } from "../predicate/isArrayLike.mjs";
|
||
|
|
import { iteratee } from "../util/iteratee.mjs";
|
||
|
|
import { isObjectLike } from "../predicate/isObjectLike.mjs";
|
||
|
|
import { reduce } from "./reduce.mjs";
|
||
|
|
//#region src/compat/array/keyBy.ts
|
||
|
|
/**
|
||
|
|
* Maps each element of an array or an object based on a provided key-generating function.
|
||
|
|
*
|
||
|
|
* This function takes an array or object and a function that generates a key from each element or value. It returns
|
||
|
|
* an object where the keys are the generated keys and the values are the corresponding elements or values.
|
||
|
|
* If there are multiple elements or values generating the same key, the last one among them is used
|
||
|
|
* as the value.
|
||
|
|
*
|
||
|
|
* @param {ArrayLike<T> | null | undefined} collection - The collection to iterate over.
|
||
|
|
* @param {Function | PropertyKey | Array | Object} [iteratee] - The iteratee to transform keys.
|
||
|
|
* - If a function is provided, it's invoked for each element in the collection.
|
||
|
|
* - If a property name (string) is provided, that property of each element is used as the key.
|
||
|
|
* - If a property-value pair (array) is provided, elements with matching property values are used.
|
||
|
|
* - If a partial object is provided, elements with matching properties are used.
|
||
|
|
* - If omitted, the identity function is used.
|
||
|
|
* @returns {Object} Returns the composed aggregate object.
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* // Using an array of objects
|
||
|
|
* keyBy([{ id: 'a' }, { id: 'b' }], 'id');
|
||
|
|
* // => { a: { id: 'a' }, b: { id: 'b' } }
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* // Using a function iteratee
|
||
|
|
* keyBy(['a', 'b', 'c'], val => val.toUpperCase());
|
||
|
|
* // => { A: 'a', B: 'b', C: 'c' }
|
||
|
|
*/
|
||
|
|
function keyBy(collection, iteratee$1) {
|
||
|
|
if (!isArrayLike(collection) && !isObjectLike(collection)) return {};
|
||
|
|
const keyFn = iteratee(iteratee$1 ?? identity);
|
||
|
|
return reduce(collection, (result, value) => {
|
||
|
|
const key = keyFn(value);
|
||
|
|
result[key] = value;
|
||
|
|
return result;
|
||
|
|
}, {});
|
||
|
|
}
|
||
|
|
//#endregion
|
||
|
|
export { keyBy };
|