reverseString

Reverse a string.

Usage

var reverseString = require( '@stdlib/string/reverse' );

reverseString( str[, options] )

Reverses a string.

var out = reverseString( 'last man standing' );
// returns 'gnidnats nam tsal'

out = reverseString( 'Hidden Treasures' );
// returns 'serusaerT neddiH'

out = reverseString( 'Lorem ipsum 𝌆 dolor sit ameͨ͆t.' );
// returns '.teͨ͆ma tis rolod 𝌆 muspi meroL'

The function supports the following options:

mode: type of characters to reverse. Must be one of the following:
- 'grapheme': grapheme clusters. Appropriate for strings containing visual characters which can span multiple Unicode code points (e.g., emoji).
- 'code_point': Unicode code points. Appropriate for strings containing visual characters which are comprised of more than one Unicode code unit (e.g., ideographic symbols and punctuation and mathematical alphanumerics).
- 'code_unit': UTF-16 code units. Appropriate for strings containing visual characters drawn from the basic multilingual plane (BMP) (e.g., common characters, such as those from the Latin, Greek, and Cyrillic alphabets).
Default: 'grapheme'.

Notes

By default, the function assumes the general case in which an input string may contain an arbitrary number of grapheme clusters. This assumption comes with a performance cost. Accordingly, if an input string is known to only contain visual characters of a particular type (e.g., only alphanumeric), one can achieve better performance by specifying the appropriate mode option.

Examples

var reverseString = require( '@stdlib/string/reverse' );

var str = reverseString( 'last man standing' );
// returns 'gnidnats nam tsal'

str = reverseString( 'presidential election' );
// returns 'noitcele laitnediserp'

str = reverseString( 'javaScript' );
// returns 'tpircSavaj'

str = reverseString( 'Hidden Treasures' );
// returns 'serusaerT neddiH'

CLI

Usage

Usage: reverse [options] [<string>]

Options:

  -h,    --help                Print this message.
  -V,    --version             Print the package version.
         --split sep           Delimiter for stdin data. Default: '/\\r?\\n/'.
         --mode mode           Type of character to return. Default: 'grapheme'.

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 $'beep\nboop' | reverse --split /\r?\n/

# Escaped...
$ echo -n $'beep\nboop' | reverse --split /\\r?\\n/

The implementation ignores trailing delimiters.

Examples

$ reverse foobar
raboof

To use as a standard stream,

$ echo -n 'foobar' | reverse
raboof

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 'foobar\tbaz' | reverse --split '\t'
raboof
zab