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.
代码片段
const isBrowser = () => ![typeof window, typeof document].includes('undefined');
使用样例
isBrowser(); // true (browser)
isBrowser(); // false (Node)