isValidSheetId
function isValidSheetId(value: unknown): value is number;
Apps Script numbers its sheets from zero, so a sheet id is a non-negative safe integer — the same rule isCountable applies. The id of the first sheet in a spreadsheet is 0.
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 sheet id; otherwise false.
In TypeScript the guard narrows value to number inside the branch.
Examples
What passes and what does not
isValidSheetId(0); // => true
isValidSheetId(1234567890); // => true
isValidSheetId(-1); // => false
isValidSheetId(1.5); // => false
isValidSheetId("0"); // => false
See also
Source
23 September 2026
This documentation was generated with AI (Claude) from the library's source code.