The "new" keyword

[taubate]

Obviously, when it comes to simple value types like int, "new" is not needed. But I have noticed that the "new" keyword is not used in other, not-so-obvious cases (e.g. DataColumn).

How can I determine if the "new" needs to be used? Thanks!

 

[chiph]

"new" is required when instantiating a reference type yourself. There are certain objects (like you've seen) that act as class factories and return you an instantiated object.

The best way to determine if you need to call it or not is to use the online help. If the object has a constructor listed you're probably OK to instantiate it yourself. But it always pays to look around at related classes to see if a method on one of them will return you an instance.

Chip H.

 

[taubate]

So, a general rule of thumb is that if an objector has a constrcutor, use "new"; if not, "new" is probably not needed.

Am I right?

 

[chiph]

A public constructor, maybe. It still may be the case where the object is normally built by calling a method on another object.

A good example of this is the SqlParameter. It has four or five constructors, and you can call 'new' on it, but the usual way of creating one is to call the CreateParameter method of the SqlCommand object, which returns one to you.

Chip H.

 

[taubate]

Thanks, Chip H!