54 lines
1.3 KiB
JavaScript
54 lines
1.3 KiB
JavaScript
|
/**
|
||
|
* @license Apache-2.0
|
||
|
*
|
||
|
* Copyright (c) 2018 The Stdlib Authors.
|
||
|
*
|
||
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
* you may not use this file except in compliance with the License.
|
||
|
* You may obtain a copy of the License at
|
||
|
*
|
||
|
* http://www.apache.org/licenses/LICENSE-2.0
|
||
|
*
|
||
|
* Unless required by applicable law or agreed to in writing, software
|
||
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
* See the License for the specific language governing permissions and
|
||
|
* limitations under the License.
|
||
|
*/
|
||
|
|
||
|
'use strict';
|
||
|
|
||
|
// MODULES //
|
||
|
|
||
|
var isNumber = require( './../../is-number' ).isPrimitive;
|
||
|
var NINF = require( '@stdlib/constants/float64/ninf' );
|
||
|
|
||
|
|
||
|
// MAIN //
|
||
|
|
||
|
/**
|
||
|
* Tests if a value is a number primitive equal to negative zero.
|
||
|
*
|
||
|
* @param {*} value - value to test
|
||
|
* @returns {boolean} boolean indicating if a value is a number primitive equal to negative zero
|
||
|
*
|
||
|
* @example
|
||
|
* var bool = isNegativeZero( -0.0 );
|
||
|
* // returns true
|
||
|
*
|
||
|
* @example
|
||
|
* var bool = isNegativeZero( new Number( -0.0 ) );
|
||
|
* // returns false
|
||
|
*/
|
||
|
function isNegativeZero( value ) {
|
||
|
return (
|
||
|
isNumber( value ) &&
|
||
|
( 1.0 / value ) === NINF
|
||
|
);
|
||
|
}
|
||
|
|
||
|
|
||
|
// EXPORTS //
|
||
|
|
||
|
module.exports = isNegativeZero;
|