function islogical islogical(x: unknown): x is boolean Checks if the input is a boolean. Returns true if the input is of type boolean. Examples Boolean true import { assertEquals } from "jsr:@std/assert"; assertEquals(islogical(true), true); Boolean false import { assertEquals } from "jsr:@std/assert"; assertEquals(islogical(false), true); Not a boolean (number) import { assertEquals } from "jsr:@std/assert"; assertEquals(islogical(1), false); Not a boolean (string) import { assertEquals } from "jsr:@std/assert"; assertEquals(islogical("true"), false); Parameters x: unknown The input to check. Return Type x is boolean Returns true if x is a boolean. Throws Throws an error if no argument is provided.