time-to-botec

Benchmark sampling in different programming languages
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main.js (2134B)

      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 isDateObject = require( './../../is-date-object' );
     24 var isInteger = require( './../../is-integer' ).isPrimitive;
     25 
     26 
     27 // MAIN //
     28 
     29 /**
     30 * Tests whether a value corresponds to a leap year in the Gregorian calendar.
     31 *
     32 * ## Notes
     33 *
     34 * -   According to the Gregorian calendar, every year that is exactly divisible by `4` is a leap year, except those years which are also divisible by `100` and not by `400` (e.g., `1900`).
     35 *
     36 * @param {*} [value] - input value
     37 * @returns {boolean} boolean whether a value corresponds to a leap year
     38 *
     39 * @example
     40 * var bool = isLeapYear();
     41 * // returns <boolean>
     42 *
     43 * @example
     44 * var bool = isLeapYear( new Date() );
     45 * // returns <boolean>
     46 *
     47 * @example
     48 * var bool = isLeapYear( 1996 );
     49 * // returns true
     50 *
     51 * @example
     52 * var bool = isLeapYear( 2001 );
     53 * // returns false
     54 */
     55 function isLeapYear( value ) {
     56 	var yr;
     57 	if ( arguments.length ) {
     58 		if ( isDateObject( value ) ) {
     59 			yr = value.getFullYear();
     60 		} else if ( isInteger( value ) ) {
     61 			yr = value;
     62 		} else {
     63 			return false;
     64 		}
     65 	} else {
     66 		// Note: cannot cache, as possible for application to cross into a new year:
     67 		yr = ( new Date() ).getFullYear();
     68 	}
     69 	// Special case if year is a new century...
     70 	if ( (yr % 100) === 0 ) {
     71 		// Centuries are only leap years at the end of "leap cycles" which happen every `400` years:
     72 		return ( (yr % 400) === 0 );
     73 	}
     74 	// All other years which are exactly divisible by `4` are leap years:
     75 	return ( (yr % 4) === 0 );
     76 }
     77 
     78 
     79 // EXPORTS //
     80 
     81 module.exports = isLeapYear;