// Figure 11.12: fig11_12.cpp #include #include using namespace std; int main() { string s1("happy"); string s2(" birthday"); string s3; // Test overloaded equality and relational operators cout << "string s1 is: " << s1 << endl; cout << "string s2 is: " << s2 << endl; cout << "string s3 is: " << s3 << endl; cout << "\n\nThe result of comparing strings s1 and s2 :" << "\ns1 == s2 yields " << (s1 == s2 ? "True" :"False") << "\ns1 != s2 yields " << (s1 != s2 ? "True" :"False") << "\ns1 < s2 yields " << (s1 < s2 ? "True" :"False") << "\ns1 > s2 yields " << (s1 > s2 ? "True" :"False") << "\ns1 <= s2 yields " << (s1 <= s2 ? "True" :"False") << "\ns1 >= s2 yields " << (s1 >= s2 ? "True" :"False"); // Test string member-functions empty cout << "\n\nTesting s3.empty() :" << endl; if (s3.empty()) { cout << "string s3 is empty; now we assigning s1 to s3 ;" << endl; s3 = s1; // assign s1 to s3 cout << "\nstring s3 is: " << s3; } // end-if // Test overloaded string concaenation operator cout << "\n\ns1 += s2 yield s1 = " ; s1 += s2; // test overloaded concatenation cout << s1; // s1 = s1 + s2 = "happy" + "birthday" = "happy birthday" //Test overloaded string concatenation operator with C-style string cout << "\n\ns1 += to you yields " << s1 + " to you"<

class string c++ STL