Formula Calculation

Sathya Narayan

hi,

I am trying to calculate the internal marks of an student.Taking 4 textboxes in that 3 textboxes for internals marks and 4th textbox for calculating the average marks of the student
i am getting an error message while calculating the values using this formula.

This is my code

public void TotalMarks(double m1, double m2, double m3)
{
double fm;
double sm;
double avg;
if((m1>=m2 )&(m1>=m3))
{
fm = m1;
if (m2 >= m3)
{
sm = m2;
}
else
{
sm = m3;

}
}
if ((m2 >= m3) & (m2 >= m1))
{
fm = m2;
if (m1 >= m3)
{
sm = m3;
}
else
{
sm = m3;

}
}
if ((m3 >= m2) & (m3 >= m1))
{
fm = m1;
if (m1 >= m2)
{
sm = m1;
}
else
{
sm = m2;

}
}

avg = (fm+sm) / 2; // error unassinged local variable fm and sm
}

private void txtfi_TextChanged(object sender, EventArgs e)
{
txtam.Text = TotalMarks((txtfi.Text), (txtsi.Text), (txtti.Text)); //error cannot convert string to double
}

private void txtsi_TextChanged(object sender, EventArgs e)
{
txtam.Text = TotalMarks((txtfi.Text), (txtsi.Text), (txtti.Text)); //error cannot convert string to double
}

private void txtti_TextChanged(object sender, EventArgs e)
{
txtam.Text = TotalMarks((txtfi.Text), (txtsi.Text), (txtti.Text)); //error cannot convert string to double
}

}
can any one please help?

3 Replies

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Jignesh Trivedi12y ago
hi,
instead of checking string.IsNullOrEmpty every time you can use int.TryParse or double.TryParse
so now your code become
private void txtfi_TextChanged(object sender, EventArgs e)
        {
            double fi = 0;
            double si = 0;
            double ti = 0;
     double.TryParse(txtfi.Text, out fi);
     double.TryParse(txtsi.Text, out si);
     double.TryParse(txtti.Text, out ti);
            txtam.Text = TotalMarks(fi, si, ti).ToString();
        }
try this and let me know you have any query.
0
Sathya Narayan12y ago
hi,

Thanks for your reply now everything is working fine

regards,

sathya
0
Princy Gupta12y ago
try the following
public Double TotalMarks(double m1, double m2, double m3)
        {
            double fm = 0;
            double sm = 0;
            double avg = 0;
            if ((m1 >= m2) & (m1 >= m3))
            {
                fm = m1;
                if (m2 >= m3)
                {
                    sm = m2;
                }
                else
                {
                    sm = m3;
                }
            }
            if ((m2 >= m3) & (m2 >= m1))
            {
                fm = m2;
                if (m1 >= m3)
                {
                    sm = m3;
                }
                else
                {
                    sm = m3;

                }
            }
            if ((m3 >= m2) & (m3 >= m1))
            {
                fm = m1;
                if (m1 >= m2)
                {
                    sm = m1;
                }
                else
                {
                    sm = m2;

                }
            }

            return avg = (fm + sm) / 2; // error unassinged local variable fm and sm
        }

        private void txtfi_TextChanged(object sender, EventArgs e)
        {
            double fi = 0;
            double si = 0;
            double ti = 0;
            if (!String.IsNullOrEmpty(txtfi.Text))
                fi = Convert.ToDouble(txtfi.Text);
            if (!String.IsNullOrEmpty(txtsi.Text))
                si = Convert.ToDouble(txtsi.Text);
            if (!String.IsNullOrEmpty(txtti.Text))
                ti = Convert.ToDouble(txtti.Text);
            txtam.Text = TotalMarks(fi, si, ti).ToString();//error cannot convert string to double
        }

        private void txtsi_TextChanged(object sender, EventArgs e)
        {
            double fi = 0;
            double si = 0;
            double ti = 0;
            if (!String.IsNullOrEmpty(txtfi.Text))
                fi = Convert.ToDouble(txtfi.Text);
            if (!String.IsNullOrEmpty(txtsi.Text))
                si = Convert.ToDouble(txtsi.Text);
            if (!String.IsNullOrEmpty(txtti.Text))
                ti = Convert.ToDouble(txtti.Text);
            txtam.Text = TotalMarks(fi, si, ti).ToString(); //error cannot convert string to double
        }

        private void txtti_TextChanged(object sender, EventArgs e)
        {
            double fi = 0;
            double si = 0;
            double ti = 0;
            if (!String.IsNullOrEmpty(txtfi.Text))
                fi = Convert.ToDouble(txtfi.Text);
            if (!String.IsNullOrEmpty(txtsi.Text))
                si = Convert.ToDouble(txtsi.Text);
            if (!String.IsNullOrEmpty(txtti.Text))
                ti = Convert.ToDouble(txtti.Text);
            txtam.Text = TotalMarks(fi, si, ti).ToString(); //error cannot convert string to double
        }
0