8ee50178f3
Correct: `Array.from()` (it’s a static method) Incorrect: `Array.join()` (doesn’t exist; it’s a prototype method) This patch uses the common `#` syntax to denote `.prototype.`.
17 lines
740 B
Markdown
17 lines
740 B
Markdown
### isBrowser
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Determines if the current runtime environment is a browser so that front-end modules can run on the server (Node) without throwing errors.
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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`.
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`typeof` allows globals to be checked for existence without throwing a `ReferenceError`.
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If both of them are not `undefined`, then the current environment is assumed to be a browser.
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```js
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const isBrowser = () => ![typeof window, typeof document].includes('undefined');
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```
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```js
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isBrowser(); // true (browser)
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isBrowser(); // false (Node)
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```
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