PHPOffice / PhpSpreadsheet

     * @param string $subData

     * @return array

     */

    private static function readUnicodeStringShort($subData)

    {

        $value = '';

        // offset: 0: size: 1; length of the string (character count)

        $characterCount = ord($subData[0]);

        $string = self::readUnicodeString(substr($subData, 1), $characterCount);

        // add 1 for the string length

        $string['size'] += 1;

        return $string;

    }

    /**

     * Extracts an Excel Unicode long string (16-bit string length)

     * @param string $subData

     * @return array

     */

    private static function readUnicodeStringLong($subData)

    {

        $value = '';

        // offset: 0: size: 2; length of the string (character count)

        $characterCount = self::getInt2d($subData, 0);

        $string = self::readUnicodeString(substr($subData, 2), $characterCount);

        // add 2 for the string length

        $string['size'] += 2;

        return $string;

    }

    /**

     * Read Unicode string with no string length field, but with known character count