# UTF-16 Unpaired Surrogate > [Regular expression][mdn-regexp] to match an unpaired [UTF-16][utf-16] surrogate.
## Usage ```javascript var reUtf16UnpairedSurrogate = require( '@stdlib/regexp/utf16-unpaired-surrogate' ); ``` #### reUtf16UnpairedSurrogate() Returns a [regular expression][mdn-regexp] to match an unpaired [UTF-16][utf-16] surrogate. ```javascript var RE_UTF16_UNPAIRED_SURROGATE = reUtf16UnpairedSurrogate(); var bool = RE_UTF16_UNPAIRED_SURROGATE.test( 'abc\uD800def' ); // returns true ``` #### reUtf16UnpairedSurrogate.REGEXP [Regular expression][mdn-regexp] to match an unpaired [UTF-16][utf-16] surrogate. ```javascript var bool = reUtf16UnpairedSurrogate.REGEXP.test( 'abc\uD800def' ); // returns true ```
## Examples ```javascript var reUtf16UnpairedSurrogate = require( '@stdlib/regexp/utf16-unpaired-surrogate' ); var RE_UTF16_UNPAIRED_SURROGATE = reUtf16UnpairedSurrogate(); var bool = RE_UTF16_UNPAIRED_SURROGATE.test( '\uD800' ); // returns true bool = RE_UTF16_UNPAIRED_SURROGATE.test( '\uDC00' ); // returns true bool = RE_UTF16_UNPAIRED_SURROGATE.test( 'abc' ); // returns false ```