isFunction (Lodash Compatibility)

Use es-toolkit's isFunction instead

This isFunction function operates slowly due to complex handling for Lodash compatibility.

Use the faster and more modern es-toolkit's isFunction instead.

Checks if a value is a function.

const result = isFunction(value);

Reference

isFunction(value)

Use isFunction when you want to type-safely check if a value is a function. It also works as a type guard in TypeScript.

import { isFunction } from 'es-toolkit/compat';

// Regular functions
isFunction(function () {}); // true
isFunction(() => {}); // true

// Built-in functions and constructors
isFunction(Array.prototype.slice); // true
isFunction(Proxy); // true
isFunction(Int8Array); // true

// Async functions and generator functions
isFunction(async function () {}); // true
isFunction(function* () {}); // true

// Other types return false
isFunction('function'); // false
isFunction({}); // false
isFunction([]); // false
isFunction(null); // false
isFunction(undefined); // false
isFunction(123); // false

Parameters

• value (unknown): The value to check if it's a function.

Returns

(value is (...args: any[]) => any): Returns true if the value is a function, false otherwise.