Use of Getter-Setter Function in C++

#include<iostream>
using namespace std;
using std::cout;
using std::cin;

#include<string>
using std::string;
using std::getline;



class book
{
private: string Book_Title;
private: int Book_ISBN;
private: string Author_Name;

  //defualt constructor
  public: book()
  {
  }
 
  //Setter Functions
  public: void setbook(string tit, string A_name, int isbn)
  {
      Book_Title=tit;
      Author_Name=A_name;         
      Book_ISBN=isbn;     
  }

  // getter Functions
  public: string getbook_Title()
  {
      return Book_Title;
       
  }

  public: string getbook_Author_Name()
  {
      return Author_Name;
       
  }

  public: int getbook_ISBN()
  {
      return Book_ISBN;
       
  }

};


int main()
{
  book mybook= book();
  string Author_Name;
  string Book_Title;
  int isbn;
  cout<<"Enter the Author Name == ";
  getline(cin,Author_Name);
  cout<<"\n";
  cout<<"Enter the Book Title == ";
  getline(cin,Book_Title);
  cout<<"\n";
  cout<<"Enter the ISBN NO == ";
  cin>>isbn;
  cout<<"\n";



  mybook.setbook(Book_Title,Author_Name,isbn);

  cout<<"Book TITLE == "<<mybook.getbook_Title()<<endl;
  cout<<"Author Name == "<<mybook.getbook_Author_Name()<<endl;
  cout<<"ISBN NO == "<<mybook.getbook_ISBN()<<endl;
    
getchar();

return 0;
}