#include#include int main() { std::string str = "Hello, world!"; std::cout << str << std::endl; return 0; }
#includeint main() { std::string name = "John"; std::string greeting = "Hello, " + name + "!"; return 0; }
#includeThis code uses the `find()` and `substr()` functions of the StringData class to extract the username from an email address. It first finds the position of the "@" symbol using `find()`, and then uses `substr()` to extract the part of the string before that position. In conclusion, the cpp StringData data is a part of the STL (Standard Template Library) and provides a powerful and flexible way to work with strings in C++. It allows you to declare, initialize, and manipulate string objects with a wide range of functions and operations.int main() { std::string email = "[email protected]"; size_t at_pos = email.find('@'); std::string username = email.substr(0, at_pos); return 0; }