How do I get this for loop to display double the number of pennies every day?

private void btnCalculate_Click(object sender, EventArgs e)
    {
        int days = Int32.Parse(txtNumberOfDays.Text);
        int totalPay = 0;
        int pennies = 1;

        for (int i = 0; i < days; i  )
        {
            totalPay  = pennies;
            pennies = pennies * 2;
           
        }

        txtTotalPennies.Text = totalPay.ToString();
    }

The code below is my first attempt at this problem and I think it works correctly. Can you tell me if this code is correct?

private void btnCalculate_Click(object sender, EventArgs e)
    {
        Double NumberOfDays = Convert.ToDouble(txtNumberOfDays.Text);
        Double TotalPennies = 1;

        for (Double i = 1; i <= NumberOfDays; i  )
        {
            TotalPennies = Math.Pow(2, NumberOfDays - 1);
        }

        txtTotalPennies.Text = TotalPennies.ToString();
    }

EDITED - Is the below code correct?

 private void btnCalculate_Click(object sender, EventArgs e)
        {
            int days = Convert.ToInt32(txtNumberOfDays.Text);
            int totalPay = 0;
            int pennies = 1;

            for (int i = 0; i < days; i  )
            {
                totalPay = pennies;
                pennies = pennies * 2;
               
            }

            txtTotalPennies.Text = totalPay.ToString();
        }

CodePudding user response：

you need to convert string to int

Convert.ToInt32(string str);

so

private void btnCalculate_Click(object sender, EventArgs e)
{
    int days = Convert.ToInt32(txtNumberOfDays.Text);
    int totalPay = 0;
    int pennies = 1;

    for (int i = 0; i < days; i  )
    {
        totalPay  = pennies;
        pennies = pennies * 2;
       
    }

    txtTotalPennies.Text = totalPay.ToString();
}

CodePudding user response：

private void btnCalculate_Click(object sender, EventArgs e)
        {
            int days = Convert.ToInt32(txtNumberOfDays.Text);
            int totalPay = 0;
            int pennies = 1;

            for (int i = 0; i < days; i  )
            {
                totalPay = pennies;
                pennies = pennies * 2;
               
            }

            txtTotalPennies.Text = totalPay.ToString();
        }