คืออยากทราบเกี่ยวกับการ แปลงค่าจาก String เป็น Int คับ

int numVal = -1;
bool repeat = true;

while (repeat == true)
{
    Console.WriteLine("Enter a number between −2,147,483,648 and +2,147,483,647 (inclusive).");

    string input = Console.ReadLine();

    // ToInt32 can throw FormatException or OverflowException.
    try
    {
        numVal = Convert.ToInt32(input);
    }
    catch (FormatException e)
    {
        Console.WriteLine("Input string is not a sequence of digits.");
    }
    catch (OverflowException e)
    {
        Console.WriteLine("The number cannot fit in an Int32.");
    }
    finally
    {
        if (numVal < Int32.MaxValue)
        {
            Console.WriteLine("The new value is {0}", numVal + 1);
        }
        else
        {
            Console.WriteLine("numVal cannot be incremented beyond its current value");
        }
    }
    Console.WriteLine("Go again? Y/N");
    string go = Console.ReadLine();
    if (go == "Y" || go == "y")
    {
        repeat = true;
    }
    else
    {
        repeat = false;
    }
}
// Keep the console open in debug mode.
Console.WriteLine("Press any key to exit.");
Console.ReadKey();