isLength
function isLength(value: unknown): boolean;
A whole number from 0 up to Number.MAX_SAFE_INTEGER — the range a length property may hold.
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 valid array-like length; otherwise false.
Examples
What passes and what does not
isLength(0); // => true
isLength(42); // => true
isLength(Number.MAX_SAFE_INTEGER); // => true
isLength(-1); // => false
isLength(1.5); // => false
isLength("3"); // => false
See also
Source
23 September 2026
This documentation was generated with AI (Claude) from the library's source code.