main.js (1273B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2018 The Stdlib Authors. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 'use strict'; 20 21 // MODULES // 22 23 var typeOf = require( '@stdlib/utils/type-of' ); 24 25 26 // MAIN // 27 28 /** 29 * Tests if a value is a function. 30 * 31 * @param {*} value - value to test 32 * @returns {boolean} boolean indicating whether value is a function 33 * 34 * @example 35 * function beep() { 36 * return 'beep'; 37 * } 38 * 39 * var bool = isFunction( beep ); 40 * // returns true 41 */ 42 function isFunction( value ) { 43 // Note: cannot use `typeof` directly, as various browser engines incorrectly return `'function'` when operating on non-function objects, such as regular expressions and NodeLists. 44 return ( typeOf( value ) === 'function' ); 45 } 46 47 48 // EXPORTS // 49 50 module.exports = isFunction;