function isnull isnull(x: unknown): boolean True for null values. Returns true if the input is null, otherwise false. Examples Input is null import { assertEquals } from "jsr:@std/assert"; assertEquals(isnull(null), true); Input is undefined import { assertEquals } from "jsr:@std/assert"; assertEquals(isnull(undefined), false); Input is a number (not null) import { assertEquals } from "jsr:@std/assert"; assertEquals(isnull(0), false); Input is an empty string (not null) import { assertEquals } from "jsr:@std/assert"; assertEquals(isnull(''), false); Parameters x: unknown The element to check. Return Type boolean Returns true if x is null.