tiny-essentials
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Collection of small, essential scripts designed to be used across various projects. These simple utilities are crafted for speed, ease of use, and versatility.
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# 📦 array.mjs
A tiny utility for shuffling arrays using the good old Fisher–Yates algorithm. Simple, efficient, and perfectly random (as far as JavaScript's `Math.random()` allows, anyway).
## ✨ Features
- 📚 Uses the classic **Fisher–Yates** algorithm
- 🔄 Shuffles arrays **in-place**
- 🎯 Guarantees **uniform distribution** of permutations
- 🔍 Well-documented and easy to read
- 🧪 No dependencies — just plug and play
## 🚀 Usage
```js
import { shuffleArray } from './array.mjs';
const fruits = ['apple', 'banana', 'cherry', 'date'];
shuffleArray(fruits);
console.log(fruits); // ['banana', 'cherry', 'apple', 'date'] (order will vary)
```
> Note: The original array is shuffled in place. If you want to preserve the original order, make a copy before shuffling.
## 🧠 How It Works
This function implements the **Fisher–Yates shuffle** (also known as the Knuth shuffle), which runs in linear time and guarantees uniform randomness:
```js
while (currentIndex !== 0) {
randomIndex = Math.floor(Math.random() * currentIndex);
currentIndex--;
[items[currentIndex], items[randomIndex]] = [items[randomIndex], items[currentIndex]];
}
```
You can find the original discussion here:
🔗 https://stackoverflow.com/questions/2450954/how-to-randomize-shuffle-a-javascript-array
## 📁 API
### `shuffleArray(items: string[]): string[]`
- **items** — An array of strings to shuffle.
- **Returns** — The same array instance, but now shuffled.
# 📦 `arraySortPositions`
🔧 **Generates a comparator function** to sort an array of objects by a specified key, with optional reverse order.
## 📌 Function Signature
```js
arraySortPositions(item: string, isReverse?: boolean): (a: Object<string|number, *>, b: Object<string|number, *>) => number
```
## 🧠 Parameters
| Name | Type | Default | Description |
| ----------- | --------- | ------- | ---------------------------------------------------------- |
| `item` | `string` | — | 🔑 The key to sort the objects by. |
| `isReverse` | `boolean` | `false` | 🔄 If `true`, the sorting will be in **descending** order. |
## 🎯 Returns
🧩 A **comparator function** compatible with `Array.prototype.sort()`:
```js
(a, b) => number
```
It compares two objects based on the specified `item` key.
## 💡 Examples
```js
const arr = [{ pos: 2 }, { pos: 1 }, { pos: 3 }];
arr.sort(arraySortPositions('pos'));
// 🔼 Ascending: [{ pos: 1 }, { pos: 2 }, { pos: 3 }]
```
```js
const arr = [{ pos: 2 }, { pos: 1 }, { pos: 3 }];
arr.sort(arraySortPositions('pos', true));
// 🔽 Descending: [{ pos: 3 }, { pos: 2 }, { pos: 1 }]
```
## 🛠️ Use Case
Great for situations where you need to **dynamically sort objects** by one of their keys, such as:
* Sorting users by age
* Ordering tasks by priority
* Displaying leaderboard scores