create the counter to add students

This code assumes that you already have a form (Form1) with a button (Button1) and a label (Label1).

public class Form1 : Form
{
    private int _studentsSoFar = 0;

    private void Button1_Click(object sender, EventArgs e)
    {
        _studentsSoFar++;
        Label1.Text = _studentsSoFar.ToString();
    }
}

You can then click the button every time a new student enters the class. When class is over, the amount of students is displayed in Label1.


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