#include "nsString.h" nsACString str("Hello world!"); // get a pointer to the string's data const char* data = str.BeginReading(); // print the string's data printf("%s\n", data);This code creates an nsACString object `str` initialized with the string "Hello world!". It then gets a pointer to `str`'s data using the `BeginReading` method, and prints it to the console using `printf()`. This example is using the Mozilla Gecko C++ library. Package/library: Mozilla Gecko C++ library.