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30-seconds-of-code/snippets/capitalize.md
2022-05-25 20:52:09 +03:00

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---
title: Capitalize string
tags: string
expertise: intermediate
cover: blog_images/digital-nomad-3.jpg
firstSeen: 2017-12-17T16:41:31+02:00
lastUpdated: 2020-11-01T20:50:57+02:00
---
Capitalizes the first letter of a string.
- Use array destructuring and `String.prototype.toUpperCase()` to capitalize the first letter of the string.
- Use `Array.prototype.join()` to combine the capitalized `first` with the `...rest` of the characters.
- Omit the `lowerRest` argument to keep the rest of the string intact, or set it to `true` to convert to lowercase.
```js
const capitalize = ([first, ...rest], lowerRest = false) =>
first.toUpperCase() +
(lowerRest ? rest.join('').toLowerCase() : rest.join(''));
```
```js
capitalize('fooBar'); // 'FooBar'
capitalize('fooBar', true); // 'Foobar'
```