@stdlib/assert-is-leap-year
    TypeScript icon, indicating that this package has built-in type declarations

    0.0.7 • Public • Published

    isLeapYear

    NPM version Build Status Coverage Status dependencies

    Test if a value corresponds to a leap year in the Gregorian calendar.

    A leap year is defined as any year which is exactly divisible by 4, except for years which are exactly divisible by 100 and not by 400. In this definition, 100 corresponds to years marking a new century, and 400 corresponds to the length of the leap cycle.

    Installation

    npm install @stdlib/assert-is-leap-year

    Usage

    var isLeapYear = require( '@stdlib/assert-is-leap-year' );

    isLeapYear( [value] )

    Tests if a value corresponds to a leap year in the Gregorian calendar.

    var bool = isLeapYear();
    // returns <boolean>
    
    bool = isLeapYear( new Date() );
    // returns <boolean>
    
    bool = isLeapYear( 2000 );
    // returns true
    
    bool = isLeapYear( 2017 );
    // returns false

    Notes

    • If not provided any arguments, the function returns a boolean indicating if the current year (according to local time) is a leap year.

    • If provided a value which is neither an integer value nor a Date, the function always returns false.

      var bool = isLeapYear( '2016' );
      // returns false
      
      bool = isLeapYear( null );
      // returns false

    Examples

    var isLeapYear = require( '@stdlib/assert-is-leap-year' );
    
    var bool;
    var i;
    
    for ( i = 0; i < 2021; i++ ) {
        bool = isLeapYear( i );
        console.log( 'The year %d %s a leap year.', i, ( bool ) ? 'is' : 'is not' );
    }

    CLI

    Installation

    To use the module as a general utility, install the module globally

    npm install -g @stdlib/assert-is-leap-year

    Usage

    Usage: is-leap-year [options] [<year>]
    
    Options:
    
      -h,    --help                Print this message.
      -V,    --version             Print the package version.
    

    Examples

    $ is-leap-year
    <boolean>
    
    $ is-leap-year 1993
    false

    To use as a standard stream,

    $ echo -n 1992 | is-leap-year
    true

    Notice

    This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

    For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

    Community

    Chat


    License

    See LICENSE.

    Copyright

    Copyright © 2016-2021. The Stdlib Authors.

    Install

    npm i @stdlib/assert-is-leap-year

    Homepage

    stdlib.io

    DownloadsWeekly Downloads

    29

    Version

    0.0.7

    License

    Apache-2.0

    Unpacked Size

    41.2 kB

    Total Files

    12

    Last publish

    Collaborators

    • stdlib-bot
    • kgryte
    • planeshifter
    • rreusser