Method charAt

Sming/Wiring/WString.h:562–565

* @brief Obtain the character at the given index * @param index * @retval char * @note If index is invalid, returns NUL \0 */

     * @note If index is invalid, returns NUL \0
     */
	char charAt(size_t index) const
	{
		return operator[](index);
	}

	/**
     * @brief Sets the character at a given index