Question

I would like to create a function that checks if a numeric value passed as an argument has a value greater than zero. Something like this:

public bool IsGreaterThanZero(object value)
{
    if(value is int)
    {
        return ((int)value > 0);
    }
    else if(value is float)
    {
        // Similar code for float
    }

    return false;
}

Can I try to cast the object passed as the function’s argument to one numeric data type so I can then compare it to zero rather than checking for each type in my if statement? If the cast fails I would return false. Is there a better(read shorter, more readable) way to do this?

Edit:
Some have asked about if I know the type will be a numeric, why the object etc. I hope this makes things clearer.

This function would be part of a Silverlight converter that implements the IValueConverter interface which has a convert signature of

public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)

A first, I only wanted the converter to work with ints but my imagination started to run wild and think what if I have floating point numbers and other numeric types. I wanted to make the converter as flexible as possible. Initially I thought all this extra information would get in the way of what I wanted to do so I didn’t include it in my question.

Answer 1

My preference would be:

public bool IsGreaterThanZero(object value)
{
    if(value is IConvertible)
    {
        return Convert.ToDouble(value) > 0.0;
    }

    return false;
}

This will handle all IConvertible types safely (which includes all floating point and integer types in the framework, but also any custom types).