> For the complete documentation index, see [llms.txt](https://thejb.gitbook.io/core/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://thejb.gitbook.io/core/programming/js/one-lines.md).
# One-lines
* ### How to Capitalize Text
```js
const capitalize = (str) => `${str.charAt(0).toUpperCase()}${str.slice(1)}`;
```
* ### How to Calculate Percent
```js
const calculatePercent = (value, total) => Math.round((value / total) * 100)
```
* ### How to Get a Random Element
```js
const getRandomItem = (items) => items[Math.floor(Math.random() * items.length)];
```
* ### How to Remove Duplicate Elements
```js
const removeDuplicates = (arr) => [...new Set(arr)];
```
* ### How to Sort Elements By Certain Property
```js
const sortBy = (arr, key) => arr.sort((a, b) => a[key] > b[key] ? 1 : a[key] < b[key] ? -1 : 0);
```
* ### How to Check if Arrays/Objects are Equal
```js
const isEqual = (a, b) => JSON.stringify(a) === JSON.stringify(b);
```
* ### How to Count Number of Occurrences
```js
const countOccurrences = (arr, value) => arr.reduce((a, v) => (v === value ? a + 1 : a), 0);
```
* ### How to Wait for a Certain Amount of Time
```js
const wait = async (milliseconds) => new Promise((resolve) => setTimeout(resolve, milliseconds));
```
* ### How to Use the Pluck Property from Array of Objects
```js
const pluck = (objs, key) => objs.map((obj) => obj[key]);
```
* ### How to Insert an Element at a Certain Position
```js
const insert = (arr, index, newItem) => [...arr.slice(0, index), newItem, ...arr.slice(index)];
```
***
> Reference