Question

I have a value that is either of a boxed (any) numeric type, or a nullable numeric type. I need to check if that value is zero or not.

Basically I have this:

public bool IsZero(object value)
{
   if (value == null)
            return false;

   //lifted from the mvc sources, so I guess it's exhaustive
   HashSet<Type> numericTypes = new HashSet<Type>(new Type[] {
        typeof(byte), typeof(sbyte),
        typeof(short), typeof(ushort),
        typeof(int), typeof(uint),
        typeof(long), typeof(ulong),
        typeof(float), typeof(double), 
        typeof(decimal)
    });

   Type type = Nullable.GetUnderlyingType(value.GetType()) ?? value.GetType();

   if (!numericTypes.Contains(type))
      return false;

   // how do I get the value here ?
}

I don’t see an easy way to compare an int value with an int zero, and a byte value with a byte zero.

One workaround I see is to associate a correctly typed zero value with every type and check against that, but I’d like to reuse the solution if I eventually I need an “IsOne” method.

Answer 1

You can combine your null check with the Convert.ToDouble method.