Replace the substring before the last occurrence of a specified search string.
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> Replace the substring before the last occurrence of a specified search string.
``bash`
npm install @stdlib/string-base-replace-before-last
`javascript`
var replaceBeforeLast = require( '@stdlib/string-base-replace-before-last' );
#### replaceBeforeLast( str, search, replacement, fromIndex )
Replaces the substring before the last occurrence of a specified search string.
`javascript
var str = 'beep boop';
var out = replaceBeforeLast( str, ' ', 'loop', str.length );
// returns 'loop boop'
out = replaceBeforeLast( str, 'o', 'bar', str.length );
// returns 'barop'
`
To begin searching from a specific index, provide a corresponding fromIndex argument.
`javascript`
var out = replaceBeforeLast( 'beep boop beep', ' ', 'loop', 5 );
// returns 'loop boop beep'
If fromIndex is less than zero, the starting index is resolved relative to the last string character, with the last string character corresponding to fromIndex = -1.
`javascript`
var out = replaceBeforeLast( 'beep boop beep', ' ', 'loop', -1 );
// returns 'loop beep'
- If a search string is not present in a provided string, the function returns the provided string unchanged.
- If a search string is an empty string, the function returns the provided string unchanged.
- If fromIndex resolves to an index which is less than 0, the function returns the provided string unchanged.
`javascript
var replaceBeforeLast = require( '@stdlib/string-base-replace-before-last' );
var str = 'beep boop';
var out = replaceBeforeLast( str, 'p', 'see', str.length );
// returns 'seep'
str = 'Hello World!';
out = replaceBeforeLast( str, 'xyz', 'foo', str.length );
// returns 'Hello World!'
str = 'Hello World!';
out = replaceBeforeLast( str, '', 'foo', str.length );
// returns 'Hello World!'
str = '';
out = replaceBeforeLast( str, 'xyz', 'foo', str.length );
// returns ''
`
*
- [@stdlib/string-base/replace-after-last][@stdlib/string/base/replace-after-last]: replace the substring after the last occurrence of a specified search string.
- [@stdlib/string-base/replace-after][@stdlib/string/base/replace-after]: replace the substring after the first occurrence of a specified search string.
- [@stdlib/string-base/replace-before][@stdlib/string/base/replace-before]: replace the substring before the first occurrence of a specified search string.
*
This package is part of [stdlib][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][stdlib], see the main project [repository][stdlib].
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---
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[@stdlib/string/base/replace-after-last]: https://www.npmjs.com/package/@stdlib/string-base-replace-after-last
[@stdlib/string/base/replace-after]: https://www.npmjs.com/package/@stdlib/string-base-replace-after
[@stdlib/string/base/replace-before]: https://www.npmjs.com/package/@stdlib/string-base-replace-before