nonRegExp
function nonRegExp<T>(value: T | RegExp): value is T;
nonRegExp(value) is the same test as !isRegExp(value), written so that a guard clause reads as a sentence rather than as a negation.
Identified by its internal tag rather than by instanceof, so a regular expression from another frame is recognised too.
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 not a regular expression; otherwise false.
In TypeScript the guard narrows value to T inside the branch.
Examples
What passes and what does not
nonRegExp("/a/"); // => true
nonRegExp({}); // => true
nonRegExp(null); // => true
nonRegExp(/a/); // => false
nonRegExp(new RegExp("a")); // => false
See also
Source
23 September 2026
This documentation was generated with AI (Claude) from the library's source code.