24 lines
881 B
Markdown
24 lines
881 B
Markdown
---
|
|
title: Environment is browser
|
|
type: snippet
|
|
language: javascript
|
|
tags: [browser]
|
|
cover: travel-mug-3
|
|
dateModified: 2020-10-20T23:02:01+03:00
|
|
---
|
|
|
|
Determines if the current runtime environment is a browser so that front-end modules can run on the server (Node) without throwing errors.
|
|
|
|
- Use `Array.prototype.includes()` on the `typeof` values of both `Window` and `Document` (globals usually only available in a browser environment unless they were explicitly defined), which will return `true` if one of them is `undefined`.
|
|
- `typeof` allows globals to be checked for existence without throwing a `ReferenceError`.
|
|
- If both of them are not `undefined`, then the current environment is assumed to be a browser.
|
|
|
|
```js
|
|
const isBrowser = () => ![typeof window, typeof document].includes('undefined');
|
|
```
|
|
|
|
```js
|
|
isBrowser(); // true (browser)
|
|
isBrowser(); // false (Node)
|
|
```
|