main.js (1029B)
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 // MAIN // 22 23 /** 24 * Tests if a double-precision floating-point numeric value is `NaN`. 25 * 26 * @param {number} x - value to test 27 * @returns {boolean} boolean indicating whether the value is `NaN` 28 * 29 * @example 30 * var bool = isnan( NaN ); 31 * // returns true 32 * 33 * @example 34 * var bool = isnan( 7.0 ); 35 * // returns false 36 */ 37 function isnan( x ) { 38 return ( x !== x ); 39 } 40 41 42 // EXPORTS // 43 44 module.exports = isnan;