Nullable types: better way to check for null or zero in c#

Question

I'm working on a project where i find i'm checking for the following in many, many places:

if(item.Rate == 0 || item.Rate == null) { } 

more as a curiousity than anything, what's the best way to check for both cases?

I've added a helper method which is:

public static bool nz(object obj) {     var parsedInt = 0;     var parsed = int.TryParse(obj.ToString(), out parsedInt);     return IsNull(obj) || (parsed && parsedInt == 0); } 

Is there a better way?

Answer 1

I like if ((item.Rate ?? 0) == 0) { }

Update 1:

You could also define an extension method like:

public static bool IsNullOrValue(this double? value, double valueToCheck) {     return (value??valueToCheck) == valueToCheck; } 

And use it like this:

if(item.IsNullOrValue(0)){} // but you don't get much from it

Answer 2

Although I quite like the accepted answer, I think that, for completeness, this option should be mentioned as well:

if (item.Rate.GetValueOrDefault() == 0) { } 

This solution

• does not require an additional method,
• is faster than all the other options, since GetValueOrDefault is a single field read operation¹ and
• reads easier than ((item.Rate ?? 0) == 0) (this might be a matter of taste, though).

---

¹ This should not influence your decision, though, since these kinds of micro-optimization are unlikely to make any difference.