To use in Observable,

substringBefore=require('https://cdn.jsdelivr.net/gh/stdlib-js/string-substring-before@umd/browser.js')

To vendor stdlib functionality and avoid installing dependency trees for Node.js, you can use the UMD server build:

varsubstringBefore=require('path/to/vendor/umd/string-substring-before/index.js')

To include the bundle in a webpage,

<scripttype="text/javascript"src="https://cdn.jsdelivr.net/gh/stdlib-js/string-substring-before@umd/browser.js"></script>

If no recognized module system is present, access bundle contents via the global scope:

<scripttype="text/javascript">(function(){window.substringBefore;})();</script>

Returns the part of a string before a specified substring.

varstr='beep boop';varout=substringBefore(str,' ');// returns 'beep'out=substringBefore(str,'o');// returns 'beep b'

• If a substring is not present in a provided string, the function returns the input string.
• If provided an empty substring, the function returns an empty string.

• @stdlib/string-substring-before-last:return the part of a string before the last occurrence of a specified substring.
• @stdlib/string-substring-after:return the part of a string after a specified substring.
• @stdlib/string-substring-after-last:return the part of a string after the last occurrence of a specified substring.

This package is part ofstdlib, 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 developstdlib, see the main projectrepository.

SeeLICENSE.

Copyright © 2016-2025. The StdlibAuthors.