Take Advantage of the ?? operator
Written October 20, 2006 at 10:41 MDT Tagged .net 2.0 and c sharp
I stumbled onto this awesome operator after a month or 2 of working with C# 2.0 (almost 2 years ago now). Take advantage of it to make your lazy initialization a lot simpler (not worrying about thread safety here). The operator simply returns the left-hand operand if it is not null otherwise it returns the right-hand operand. Take a look at the following progression of the code:
Simple If Statement:
public ISession ActiveSession
{
get
{
if(activeSession == null)
{
activeSession = mappingSessionFactory.Create();
}
return activeSession;
}
}
public ISession ActiveSession
{
get
{
if(activeSession == null) activeSession = mappingSessionFactory.Create();
return activeSession;
}
}
Further condensed by taking advantage of the ternary operator :
public ISession ActiveSession
{
get{ return (activeSession == null ? activeSession = mappingSessionFactory.Create() : activeSession); }
}
Made readable again by taking advantage of the ?? operator:
public ISession ActiveSession
{
return activeSession ?? (activeSession = mappingSessionFactory.Create()); }
}
Notice what is happening in that line? If the left hand side of the operand (the activeSession field) evaluates to null, the right-hand operand is returned; which in this case results in an initialization of the field that was null in the first place.Again, this is not new information, I just thought I would throw it out there as a reminder.
JP