#includeIn this program, we create a BString object "str" with the value "hello". We then use the Append method to add the string " world" to the end of "str". Finally, we print the result to the console. The BString class and Append method are part of the BeOS API, which was developed by Be Inc. for their BeOS operating system. The BeOS API is now largely obsolete, but some open source projects, such as Haiku, continue to use it.#include int main() { BString str = "hello"; str.Append(" world"); std::cout << str << std::endl; return 0; }