C++爱好者 - 网友留言

#include
#include
using namespace std;
class persontype{
      public:
       
             persontype(string first="",string last="");
             void print() const;
             void setname(string first,string last);
             persontype& setlastname(string last);
             persontype& setfirstname(string first);         //此处的&为什么不能去掉？
             void getname(string& first,string& last);
           
      private:
              string firstname;
              string lastname;
      };
void persontype::print()const{
     cout<<"the firstnameis"<     cout<<"the lastname is"<     }
void persontype::setname(string first,string last){
     firstname=first;
     lastname=last;
     }
persontype& persontype::setlastname(string last){
     lastname=last;
     return *this;
     }
persontype& persontype::setfirstname(string first){
     firstname=first;
     return *this;                                       //此处的return *this 好象去掉也不影响结果，为什么？
     }                                                   //那为什么要有这句？有什么作用呢？
persontype::persontype(string first,string last){
     firstname=first;
     lastname=last;
     }
int main(){
    persontype student1("huang","xianjun");
    persontype student2;
    persontype student3;
    cout<<"line 4:student1";
    student1.print();
    cout<    student2.setfirstname("yu").setlastname("guangbing");
    cout<<"line 8:student2";
    student2.print();
    cout<    student3.setfirstname("li");
    cout<<"line 12:student3";
    student3.print();
    cout<    student3.setlastname("zheng");
    cout<<"line 16:student3";
    student3.print();
    cout<    //return 0;
    system("pause");
    }
问题写在程序旁边了,高手们能不能把this指针和引用参数传递方面的讲的详细一点
小弟在此谢过

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