Question

Is there a difference (performance, overhead) between these two ways of merging data sets?

MyTypedDataSet aDataSet = new MyTypedDataSet(); aDataSet .Merge(anotherDataSet); aDataSet .Merge(yetAnotherDataSet); 

and

MyTypedDataSet aDataSet = anotherDataSet; aDataSet .Merge(yetAnotherDataSet); 

Which do you recommend?

Answer 1

While Keith is right, I suppose the example was simply badly chosen. Generally, it is better to initialize to the “right” object from the beginning and not construct an intermediate, empty object as in your case. Two reasons:

1. Performance. This should be obvious: Object creation costs time so creating less objects is better.
2. Much more important however, it better states your intent. You do generally not intend to create stateless/empty objects. Rather, you intend to create objects with some state or content. Do it. No need to create a useless (because empty) temporary.