Question

I have the following piece of code which attempts to determine whether a given string is a valid integer. If it’s an integer, but not within the valid range of Int32, I need to know specifically whether it’s greater than Int32.MaxValue or less than Int32.MinValue.

try
{
     return System.Convert.ToInt32(input);
}
catch (OverflowException)
{
     return null;
}
catch (FormatException)
{
     return null;
}

Convert.ToInt32 will throw the OverflowException if it’s not in the range of acceptable values, but it throws the same exception for both greater than and less than. Is there a way to determine which one it is aside from parsing out the text of the exception?

Answer 1

As you’re using .NET 4, you could use BigInteger – parse to that, and then compare the result with the BigInteger representations of int.MaxValue and int.MinValue.

However, I would urge you to use TryParse instead of catching an exception and using that for flow control.