isLeapYear

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

To use as a general utility, install the CLI package globally

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

Usage

Usage: is-leap-year [options] [<year>]

Options:

  -h,    --help                Print this message.
  -V,    --version             Print the package version.
         --split sep           Delimiter for stdin data. Default: '/\\r?\\n/'.

Notes

• If the split separator is a regular expression, ensure that the split option is either properly escaped or enclosed in quotes.

  # Not escaped...
  $ echo -n $'1993\n1992' | is-leap-year --split /\r?\n/
  # Escaped...
  $ echo -n $'1993\n1992' | is-leap-year --split /\\r?\\n/

• The implementation ignores trailing delimiters.

Examples

$ is-leap-year
<boolean>

$ is-leap-year 1993
false

To use as a standard stream,

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

By default, when used as a standard stream, the implementation assumes newline-delimited data. To specify an alternative delimiter, set the split option.

$ echo -n '1992\t1993' | is-leap-year --split '\t'
true
false

See Also

• @stdlib/assert-is-leap-year: test if a value corresponds to a leap year in the Gregorian calendar.

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

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.