.net - C#: Any difference whatsoever between "(subtype)data" and "data as subtype" typecasting? -

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Assuming that I have an example of something that I know is a sub-class of a specific subtype A supertype in C #, I used to see typecasting like this kind of way (assuming "reference" is supertype): 

  if (reference is subtype) { Subtype t = (sub-type) reference; }

But recently I have come in the examples of examples which have been done with the same thing in this way: 

  If (context Subtype) {subtype T = references in subtype; }

Are these two completely equal? Is there a difference?

These are used in the same way, but are not the best choice. You should only be typing once: 

  subtype t = reference as subtype; If (t! = Null) {...}

The tap is more efficient than checking the type of check.


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