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prevGraphemeClusterBreak

Return the previous extended grapheme cluster break in a string before a specified position.

Installation

npm install @stdlib/string-prev-grapheme-cluster-break

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 prevGraphemeClusterBreak = require( '@stdlib/string-prev-grapheme-cluster-break' );

prevGraphemeClusterBreak( string[, fromIndex] )

Returns the previous extended grapheme cluster break in a string before a specified position.

var out = prevGraphemeClusterBreak( 'last man standing' );
// returns 15

By default, the last extended grapheme cluster break in the string is returned. For the previous extended grapheme cluster break before a specified position in the string, provide a fromIndex.

var out = prevGraphemeClusterBreak( 'last man standing', 4 );
// returns 3

Notes

• If string is an empty string, the function returns -1 irrespective of fromIndex.
• If there is no extended grapheme cluster break before fromIndex, the function returns -1.
• Note that fromIndex does not refer to a visual character position, but to an index in the ordered sequence of UTF-16 code units.

Examples

var prevGraphemeClusterBreak = require( '@stdlib/string-prev-grapheme-cluster-break' );

console.log( prevGraphemeClusterBreak( 'last man standing', 4 ) );
// => 3

console.log( prevGraphemeClusterBreak( 'presidential election', 8 ) );
// => 7

console.log( prevGraphemeClusterBreak( 'अनुच्छेद', 2 ) );
// => 0

console.log( prevGraphemeClusterBreak( '🌷', 1 ) );
// => -1

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CLI

Installation

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

npm install -g @stdlib/string-prev-grapheme-cluster-break-cli

Usage

Usage: prev-grapheme-cluster-break [options] [<string>]

Options:

  -h,    --help                Print this message.
  -V,    --version             Print the package version.
         --fromIndex index     Position in string. Default: string.length-1.

Examples

$ prev-grapheme-cluster-break --fromIndex=2 अनुच्छेद
0

To use as a standard stream,

$ echo -n 'अनुच्छेद' | prev-grapheme-cluster-break --fromIndex=2
0

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See Also

• @stdlib/string-num-grapheme-clusters: return the number of grapheme clusters in a string.
• @stdlib/string-next-grapheme-cluster-break: return the next extended grapheme cluster break in a string after a specified position.

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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 © 2016-2024. The Stdlib Authors.