// Demo: common error
//     : in updating name in Student
#include <iostream>
#include <string>
#include <iomanip>
using namespace std;
class Student {
  private:
    string id,name,class_no;
  public:
    Student(){ id="id00";
               name="none";
               class_no="00";
               } // initial values given for very student
    void show() {
     cout << left << setw(5) << id <<
             setw(15) << name << class_no << endl;
    }
    void enter(); // enter name only
};
void Student::enter() {  // updates name to local variable
   string name;  // this SHOULD NOT be declared
   cout << "enter name ";
   getline(cin,name);
}
void main() {
 Student x,y; // create 2 students x and y
 x.show();  // display student x"id00  none  00"
 x.enter();  // enter the name "BENG" for student x
 x.show();   //  display "id00 none 00" (note BENG is not updated)
}
/* Note
The name BENG entered does not update the name of student x
because in the function enter(), a local variable "name"
was declared and the name was entered into the local variable
of enter(), but NOT the 'name' attribute in Student.
*/