requireRegExp
function requireRegExp(value: unknown, message: string = "Expected a regular expression."): RegExp;
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 validate. |
|
| The message of the exception. A default is used when omitted. |
Returns
RegExp — the same value, typed as a regular expression.
Throws
Exception | Condition |
|---|---|
| the value is not a regular expression. |
Examples
What passes and what does not
requireRegExp(/a/); // => /a/
requireRegExp(new RegExp("a")); // => new RegExp("a")
requireRegExp("/a/"); // throws IllegalArgumentException
requireRegExp({}); // throws IllegalArgumentException
See also
Source
23 September 2026
This documentation was generated with AI (Claude) from the library's source code.