79 lines
1.9 KiB
JavaScript
79 lines
1.9 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';
|
||
|
|
|
||
|
|
// MAIN //
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Tests if two arguments are the same value.
|
||
|
|
*
|
||
|
|
* ## Notes
|
||
|
|
*
|
||
|
|
* - The function implements the [SameValue Algorithm][ecma-262-same-value-algorithm], as specified in ECMAScript 5.
|
||
|
|
* - In contrast to the strict equality operator `===`, `-0` and `+0` are distinguishable and `NaNs` are the same.
|
||
|
|
*
|
||
|
|
* [ecma-262-same-value-algorithm]: http://ecma-international.org/ecma-262/5.1/#sec-9.12
|
||
|
|
*
|
||
|
|
* @param {*} a - first input value
|
||
|
|
* @param {*} b - second input value
|
||
|
|
* @returns {boolean} boolean indicating whether two arguments are the same value
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* var bool = isSameValue( true, true );
|
||
|
|
* // returns true
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* var bool = isSameValue( 3.14, 3.14 );
|
||
|
|
* // returns true
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* var bool = isSameValue( {}, {} );
|
||
|
|
* // returns false
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* var bool = isSameValue( -0.0, -0.0 );
|
||
|
|
* // returns true
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* var bool = isSameValue( -0.0, 0.0 );
|
||
|
|
* // returns false
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* var bool = isSameValue( NaN, NaN );
|
||
|
|
* // returns true
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* var bool = isSameValue( [], [] );
|
||
|
|
* // returns false
|
||
|
|
*/
|
||
|
|
function isSameValue( a, b ) {
|
||
|
|
if ( a === b ) {
|
||
|
|
if ( a === 0.0 ) {
|
||
|
|
return 1.0 / a === 1.0 / b; // handles +-0
|
||
|
|
}
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
return ( a !== a && b !== b ); // handles NaNs
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
// EXPORTS //
|
||
|
|
|
||
|
|
module.exports = isSameValue;
|