https://github.com/whizkydee/type-reverse
🦄 Lightweight reverse utility around strings, arrays, numbers and more.
https://github.com/whizkydee/type-reverse
array inverse invert inverted-index reverse string
Last synced: 11 months ago
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🦄 Lightweight reverse utility around strings, arrays, numbers and more.
- Host: GitHub
- URL: https://github.com/whizkydee/type-reverse
- Owner: whizkydee
- License: mit
- Created: 2017-12-18T19:04:24.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2023-03-13T01:24:42.000Z (almost 3 years ago)
- Last Synced: 2024-10-16T07:04:51.834Z (over 1 year ago)
- Topics: array, inverse, invert, inverted-index, reverse, string
- Language: JavaScript
- Homepage: https://npm.im/type-reverse
- Size: 27.3 KB
- Stars: 33
- Watchers: 2
- Forks: 4
- Open Issues: 0
-
Metadata Files:
- Readme: readme.md
- Changelog: changelog.md
- License: license.md
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README
# type-reverse
[](https://travis-ci.org/whizkydee/type-reverse) [](https://github.com/facebook/jest) [](https://github.com/acekyd/made-in-nigeria)
> 🦄 Lightweight reverse utility around strings, arrays, numbers and more.
## Install
```sh
$ npm install --save type-reverse
```
## Usage
```js
const reverse = require('type-reverse')
```
or...
```js
import reverse from 'type-reverse'
```
### API
#### reverse( input[, options][, callback] )
**Params**
- `input` **{String|Number|Array|Set}**
- `options` **{?Object}**
- `callback` **{?Function}**
- `returns` **{\*}**
```js
reverse('pizza')
//=> azzip
```
Works with numbers too.
```js
reverse(1234)
//=> 4321
```
## Reversing arrays...
When JavaScript's _Array#reverse_ method is used, the original array is mutated, as in, the indexes of the elements are changed. On the other hand, this utility adopts the **non-destructive array reversal** method, which means the `reverse()` function doesn't mutate the array; it just returns the reversed array and still maintains the indexes of the elements in the original array.
#### native reverse...
```js
const arr = [1, 2, 3]
arr.reverse() //=> [3, 2, 1]
```
Oops, we lost the indexes of elements in the initial array...
```js
console.log(arr) //=> [3, 2, 1]
```
vs...
#### 🦄 to the rescue...
```js
const arr = [1, 2, 3]
reverse(arr) //=> [3, 2, 1]
```
Yay! `arr` is not mutated. The indexes of its elements are still maintained...
```js
console.log(arr) //=> [1, 2, 3]
```
### Sets
If you've been wondering how to reverse Sets in JavaScript, here's it! The core `reverse` function can take in a `Set` as the input and then return the reversed `Set`...
```js
const set = new Set([5, 4, 3, 4, 5])
reverse(set) //=> Set { 3, 4, 5 }
```
## options
`options` is the second parameter to the function call and it is an object with two available properties. It can also take in a falsy value which would implicity get converted to an empty object.
### `invert: {String}`
This property defaults to `index` and applies to strings and numbers only.
```js
reverse(/*...*/, {
invert: '[index|word|sign]'
})
```
- `index` - interchanges the indexes of characters in the input...
```js
reverse(12345, { invert: 'index' }) //=> 54321
reverse('of... unicorns', { invert: 'index' }) //=> snrocinu ...fo
```
- `sign` - inverts the sign in a number...
```js
reverse(1234, { invert: 'sign' }) //=> -1234
```
- `word` - swaps the location of words in a string...
```js
reverse('of... unicorns', { invert: 'word' }) //=> unicorns of...
```
### `preserveZeros: {Boolean}`
This property defaults to `true`. It specifies whether to enforce preceding zeros in the result of a number that contains trailing zeros. See [#3](https://github.com/whizkydee/type-reverse/issues/4) for more info. Note that the result gets converted to a string. Disabling it would look like this...
```js
reverse(240, { preserveZeros: false }) //=> 42
```
## `callback: {Function}`
The callback takes in a function with two optional parameters that represent `input` and `result` respectively.
- `input` - the initial input that was passed into the function
- `result` - the output from reversing the input
```js
const text = 'dog'
reverse(text, null, function(intitial, result) {
return intitial + ' was changed to ' + result
}) //=> dog was changed to god
```
## Limits
Did you just try to reverse a reaally huge number? Unfortunately, this utility doesn't support very large numbers. Trying to do so with this utility would throw a **TypeError**.
## Author
**Olaolu Olawuyi**
- [github/whizkydee](https://github.com/whizkydee)
- [twitter/mrolaolu](https://twitter.com/mrolaolu)
## License
MIT © [Olaolu Olawuyi](https://olaolu.me)