Cant create class object

[Zenith1900]

I'd like to create an array to accept student' names. Why cant I create the class object Quizdata student[NEW_STUDENT]; ?

#include <iostream>
#include <iomanip>
#include <string>
using namespace std;

class Quizdata
{
	private:
		 string  name;
		 double total;
		 int   number;
		 
	public:
		Quizdata(string n){
			setName(n);
			total=number=0;
		}
		
		void setName(string studentName){
			name = studentName;
		}
		string get_name(){
			return name;
		}
		int add_quiz(int, int);
			
		
		
		double get_total_score(){
			return total;
		}
		double get_average_score(){
		    return total/number;
		}
	
};

int Quizdata::add_quiz(int n, int grade)
{
	int quizNum = n;
	int score = grade; 


	while ( n!=0){
        cin>> grade;
    if (grade>=10 && grade<=100){
        total +=grade;
        number++;
    	n--;
		}	
	else 
		{
		cout << "Invalid input, score range is from 10 to 100";
		}
	}
}
    	
void printresults(Quizdata);
const int NEW_STUDENT=3;

int main()
{
    Quizdata student[NEW_STUDENT];    //???
    
        string name;
	int quizNum, score, total;
    
	cout << "This program accepts students' name,\n"
         << "number of quizes and their scores.\n"
         << "Quiz scores must be in the range of 10 to 100\n";

//*******************************************************************    
for (int index=0; index< NEW_STUDENT;index++)
{
	cout << "\nEnter the name for student " << (index+1) << ":";
    getline(cin, name);
	student[index].setName(name)
	
}

//*******************************************************************	
	
	
	cout << "How many quizes grades would you like to enter? ";
    cin >> quizNum;                                                //why cant move to add_auiz???
    cout << "Enter " << quizNum << " quize grades: "; 
    student1.add_quiz(quizNum, score);
	
 printresults(student1);



	return 0;
     
     
}


void printresults(Quizdata student1)
{
	cout << fixed << showpoint << setprecision(2) << endl;;
    cout << "\nStudent's name is:\t" << student1.get_name() <<endl;
    cout << "Student's total is:\t" << student1.get_total_score()<< endl;
    cout << "Student's average is:\t" << student1.get_average_score()<< endl;
}

[hyperfine]

In your class you need to name the arguments:

class QuizData
{
...
public:
int add_quiz (int a, int b);
...
}