prevGraphemeClusterBreak

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

Installation

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

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

See Also

• @stdlib/string-prev-grapheme-cluster-break-cli: CLI package for use as a command-line utility.
• @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.

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.