.NET 4 - Using nullable operator (??) to simplify if statements
I have this piece of code, that checks whether a returned object is null. If so, it will return 0, or else it will return a property inside the object.
var userPoints = (from Point p in entities.Point
where p.UserName == userName
select p).SingleOrDefault();
if (userPoints == null)
{
return 0;
}
else
{
return userPoints.Poi开发者_StackOverflownts;
}
Is it possible to simplify the if statements with the nullable operator? I've tried this, but the system throws an exception when attempting to read the property
return userPoints.Points ?? 0;
No, unfortunately there's nothing which will do exactly that. Options:
Use the conditional operator:
return userPoints == null ? 0 : userPoints.Points;
Change your query to make that do the defaulting:
return (from Point p in entities.Point where p.UserName == userName select p.Points).SingleOrDefault();
Personally I'd go for the latter approach :) If you wanted a default other than 0, you'd need something like:
return (from Point p in entities.Point
where p.UserName == userName
select (int?) p.Points).SingleOrDefault() ?? -1;
You can do this:
var userPoints = (from Point p in entities.Point
where p.UserName == userName
select p.Point).SingleOrDefault();
return userPoints;
If there are no results then userPoints will be 0, otherwise it will be the value of Points.
You can't use it in your context.
Explanation:
You want to check whether userPoints
is null, but want to return userPoints.Points
if it is not null.
The ??
operator checks the first operand for null and returns it, if it is not null. It doesn't work if what you want to check and what you want to return are two different things.
Hover over var
with the mouse and see what type it is.
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