isScalar
function isScalar(value: unknown): value is string | number | boolean | symbol | bigint;
A primitive that carries a single value: string, number, boolean, symbol or bigint. null and undefined are primitives too, but they carry no value and do not qualify.
isX and nonX answer a question and never interrupt control flow; requireX and requireNonX hand the value back or throw. The scheme is explained in Validation conventions.
Parameters
Parameter | Type | Description |
|---|---|---|
|
| The value to check. |
Returns
boolean — true when the value is a scalar; otherwise false.
In TypeScript the guard narrows value to string | number | boolean | symbol | bigint inside the branch.
Examples
What passes and what does not
isScalar("abc"); // => true
isScalar(1); // => true
isScalar(true); // => true
isScalar(10n); // => true
isScalar({}); // => false
isScalar([]); // => false
isScalar(null); // => false
See also
Source
23 September 2026
This documentation was generated with AI (Claude) from the library's source code.