https://github.com/ozum/scrap
Scrap repository for experiment
https://github.com/ozum/scrap
Last synced: about 2 months ago
JSON representation
Scrap repository for experiment
- Host: GitHub
- URL: https://github.com/ozum/scrap
- Owner: ozum
- License: mit
- Created: 2018-03-19T09:25:32.000Z (about 7 years ago)
- Default Branch: master
- Last Pushed: 2023-11-29T09:24:45.000Z (over 1 year ago)
- Last Synced: 2025-02-09T18:24:56.267Z (3 months ago)
- Language: JavaScript
- Size: 2.09 MB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 14
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# array-map-to-object
Like `map()`, but creates object keys and values instead of array. `mapToObject` creates a new object with the returned keys and values of calling a provided function on every element in the calling array.
Published as `.js`, `.mjs`, `umd.js` including type definitions for `TypeScript`.
# Syntax
```ts
const newObject = mapToObject(array, (currentValue[, index[, array]]) => {
// Return key for object item
// or [key, value] tuple (array) for key and value
// or { key, value } object for key and value
}, [, thisArg]);
```
# Examples
```ts
import mapToObject from "array-map-to-object";
```
## Using a property for key to create object
```ts
const users = [
{ name: "George", basketSize: 3 },
{ name: "Lisa", basketSize: 2 },
];
const usersLookup = mapToObject(users, "name");
// { George: { name: "George", basketSize: 3 }, Lisa: { name: "Lisa", basketSize: 2 } }
```
```ts
const users = [
{ name: "George", basketSize: 3 },
{ name: "Lisa", basketSize: 2 },
];
const usersLookup = mapToObject(users, (user) => user.name);
// Callback returns only key, value is same item. `usersLookup` is:
// { George: { name: "George", basketSize: 3 }, Lisa: { name: "Lisa", basketSize: 2 } }
```
## Creating custom object using key/value pair.
```ts
const users = [
{ name: "George", basketSize: 3 },
{ name: "Lisa", basketSize: 2 },
];
const usersLookup = mapToObject(users, (user) => [user.name, user.basketSize]);
// Callback returns [key, value] tuple (array). First returned value used for key, second for value. `usersLookup` is:
// { George: 3, Lisa: 2 }
```
## Creating custom object using key/value object.
```ts
const users = [
{ name: "George", basketSize: 3 },
{ name: "Lisa", basketSize: 2 },
];
const usersLookup = mapToObject(users, (user) => ({
key: user.name,
value: user.basketSize,
}));
// Callback returns { key, value } object. `usersLookup` is:
// { George: 3, Lisa: 2 }
```
## Mapping an array of numbers to an array of square roots
```ts
const numbers = [1, 4, 9];
const roots = mapToObject(numbers, (num) => [num, Math.sqrt(num)]);
// `roots` is { 1: 1, 4: 2, 9: 3 }
```