isfunction - datatype/isfunction.ts

function isfunction



isfunction(x: unknown): boolean

Checks if the input is a function.

Returns true if the input is of type function.

Examples

Inline function

import { assertEquals } from "jsr:@std/assert";

assertEquals(isfunction(function() { return console.log("Hello"); }), true, 'Inline function should return true');

Built-in function

import { assertEquals } from "jsr:@std/assert";

assertEquals(isfunction(Math.log), true, 'Built-in function should return true');

Not a function (number)

import { assertEquals } from "jsr:@std/assert";

assertEquals(isfunction(42), false, 'Number should return false');

Not a function (string)

import { assertEquals } from "jsr:@std/assert";

assertEquals(isfunction("hello"), false, 'String should return false');

Parameters



x: unknown

The input to check.

Return Type

boolean

Returns true if x is a function.

Throws

Throws an error if no argument is provided.