39. Which of the following is true about the library string class or the textbook example String class?

Group of answer choices

The class interface contains a character array data member to hold the string

All of these

If the character array overflows, the class copy constructor creates linked list with another char array to hold the additional characters

The class interface contains a character pointer to the string

40.Which line of code will complete the constructor from the textbook example String class?

class String { public: String(); // Default constructor String(const char s[]) { len = strlen(s); if (len > 0) { _____________________________//line of code goes here for (int i = 0; i < len; i++) { buffer[i] = s[i]; } } else { buffer = nullptr; } } private: char* buffer; int len; };

Group of answer choices

char buffer[len];

char buffer[len+1];

buffer = new char[len];

char* buffer = new char[len];