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isDurationString

Test if a value is a duration string.

Installation

npm install @stdlib/assert-is-duration-string

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).
• To use as a general utility for the command line, install the corresponding CLI package globally.

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

Usage

var isDurationString = require( '@stdlib/assert-is-duration-string' );

isDurationString( value )

Tests if a value is a duration string.

var bool = isDurationString( '1d' );
// returns true

bool = isDurationString( '1d2h' );
// returns true

Notes

• The function validates that a value is a string. For all other types, the function returns false.

• A duration string is a string containing a sequence of time units. A time unit is a nonnegative integer followed by a unit identifier. The following unit identifiers are supported:

  • d: days
  • h: hours
  • m: minutes
  • s: seconds
  • ms: milliseconds

  For example, the string 1m3s10ms is a duration string containing three time units: 1m (1 minute), 3s (3 seconds), and 10ms (10 milliseconds). The string 60m is a duration string containing a single time unit: 60m (60 minutes). Time units must be supplied in descending order of magnitude (i.e., days, hours, minutes, seconds, milliseconds).

• Duration strings are case insensitive. For example, the string 1M3S10MS is equivalent to 1m3s10ms.

Examples

var isDurationString = require( '@stdlib/assert-is-duration-string' );

var bool = isDurationString( '1h' );
// returns true

bool = isDurationString( '1m20ms' );
// returns true

bool = isDurationString( '1d 2h 3m 4s' );
// returns false

bool = isDurationString( 'beep' );
// returns false

bool = isDurationString( null );
// returns false

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CLI

Installation

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

npm install -g @stdlib/assert-is-duration-string-cli

Usage

Usage: is-duration-string [options] [<string>]

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 $'3m20s\n50ms' | is-duration-string --split /\r?\n/
  # Escaped...
  $ echo -n $'3m20s\n50ms' | is-duration-string --split /\\r?\\n/

• The implementation ignores trailing delimiters.

Examples

$ is-duration-string '1h'
true

To use as a standard stream,

$ echo -n '1x' | is-duration-string
false

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 '1h2m3s\tboop' | is-duration-string --split '\t'
true
false

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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

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License

See LICENSE.

Copyright

Copyright © 2016-2025. The Stdlib Authors.