如何从列表框中计算字符串列表的数量并相乘？

Question

I have written a code here. It loops through. I have used an if statement to check if Fizz has printed three times in the ListBox. If it has, I would like a simple calculation with multiplication of 3. Then, prints out the value in the TextBox.

So, Fizz prints three times it will multiply my 3 which equals 9. How do I convert the string in the Listbox to int so that it can calculate `3 x 3 = 9, if that's how it should be done.

string Output = "Fizz";

for (int a = 1; a <= 10; a++)
{
    if (a == 3)
    {
        for (int b = 1; b <= 3; b++)
        {
            listBox4.Items.Add(Output);
            int multiplyBy = 3; 
            //int numVal = Int32.Parse("3");
            listBox4.Items.Count.ToString();  
        }

        textBox1.Text = listBox4.Items.Count.ToString();            
    }
}

Thanks if anyone can help me.

Answer 1

Use Int32.Parse or Convert.ToInt32

See MSDN https://msdn.microsoft.com/en-us/library/bb397679.aspx

and MSDN https://msdn.microsoft.com/en-us/library/system.int32.parse(v=vs.110).aspx

Answer 2

Not sure what you want, but I will give it a try based on what you wrote:

string output = "Fizz";

// Loop from 1 to 10 for no reason
for (int a = 1; a <= 10; a++)
{
    // Add "Fizz" item to listbox 3 times if 'a' equals 3
    if (a == 3)
    {
        for (int b = 1; b <= 3; b++)
        {
            listBox1.Items.Add(output);
        }

        // Multiply number of items in listBox with 3 for no reason and display it in textbox
        textBox1.Text = (listBox1.Items.Count * 3).ToString();
    }
}