Question

I’m new to C++ and am not sure what’s wrong. This is a task I have been given in my programmging course at uni which is meant to take user input of a vector of grades and determine whether the grade is a passing one. When I compile I end up getting an error stating q1.cpp:30:21: error: could not convert ‘y’ from ‘int’ to ‘std::vector’
Not overly sure why. Sorry about the bad formatting.

I’ve added the code but not sure how to wrap it.

#include <vector>
#include <cstdlib>
#include <iostream>

using namespace std;

int calcNumberOfPasses(vector<int> grades){
int x;
    for (int i=0; i<grades.size(); i++){
        cin >>grades[i];
    }
    cin >> x;
}



int main() {
    int y;
    vector<int> nGrade;
    nGrade.push_back(y);
    cout << "Enter how many grades you want to enter";
    for (int i=0; i<nGrade.size();i++){
        cin >> nGrade[i];
    }
    cin >> y;
    if (y>=50){
        cout << "this is a passing grade";
    }
    calcNumberOfPasses(y);
}

Answer 1

The function calcNumberOfPasses is expecting a parameter of type vector<int>, you are passing it a parameter of type int. That much you can work out from the error message.

You are copying an undefined value into the vector on this line:

nGrade.push_back(y); // y hasn't been initialised yet, you probably want to remove this line.

Following that you are looping over the size of the grades vector, which hasn’t been initialised yet.

Chances are, you want to do calcNumberOfPasses(nGrades);.

As an aside, you should use a reference to the vector, to avoid copying it.

In summary, I would through all of this code away and start again. No offence!