requireArray
function requireArray<T>(value: unknown, message: string = "Expected an array."): T[];
Array.isArray is the whole test, so an array from another frame counts and an array-like object — arguments, a NodeList, { length: 0 } — does not.
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
T[] — the same value, typed as an array.
Throws
Exception | Condition |
|---|---|
| the value is not an array. |
Examples
What passes and what does not
requireArray([]); // => []
requireArray([1, 2, 3]); // => [1, 2, 3]
requireArray("abc"); // throws IllegalArgumentException
requireArray({ length: 0 }); // throws IllegalArgumentException
See also
Source
23 September 2026
This documentation was generated with AI (Claude) from the library's source code.