@zerodep/is-function

A simple, performant utility to determine if a value is a function.

Full documentation is available at the zerodep.app page.

Examples

All @zerodep packages support both ESM and CJS.

import { isFunction } from '@zerodep/is-function';
// or
const { isFunction } = require('@zerodep/is-function');

Positive Response

isFunction(() => 'function'); // true
isFunction(new Function('return true')); // true

Negative Response

isFunction(['a', 'b', 'c']); // false
isFunction(1000n); // false
isFunction(true); // false
isFunction(new Date()); // false
isFunction(''); // false
isFunction(new Error('message')); // false
isFunction(3.14); // false
isFunction(42); // false
isFunction(
  new Map([
    ['a', 1],
    ['b', 2],
  ])
); // false
isFunction(null); // false
isFunction({ an: 'object' }); // false
isFunction(new Promise(() => {})); // false
isFunction(/[regex]+/gi); // false
isFunction(new Set([1, 2, 3])); // false
isFunction('a string'); // false
isFunction(Symbol()); // false
isFunction(new Int32Array(2)); // false
isFunction(undefined); // false