apps-script-utils 2.1.1 Help

isNull

function isNull(value: unknown): value is null;

Strictly null. undefined is a separate case — isNil covers both.

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

value

unknown

The value to check.

Returns

boolean — true when the value is null; otherwise false.

In TypeScript the guard narrows value to null inside the branch.

Examples

What passes and what does not

isNull(null); // => true isNull(undefined); // => false isNull(0); // => false isNull(""); // => false

See also

Source

src/lang/base/isNull.ts

23 September 2026
isNonNegativeisNumber

This documentation was generated with AI (Claude) from the library's source code.