dynamic_cast in RTTI C++

[madhuti]

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In what situations we have to use RTTI dynamic_cast mechanism.
What is the difference between dynamic_cast and static_cast

First I have searched in net. But I didn't the right one. So, I am posting here.

Thanks in Adavance,
MAdhu

[Roxoff]

dynamic_cast checks the known type information for the instance pointed at - if the instance could be of the type requested, a pointer to that type is returned. Otherwise it returns NULL. You'd usually use dynamic_cast to change a pointer to a class instance to another class in the instance's class heirarchy.

static_cast just changes the type without making checks to see if anything is valid.

If this is a homework question, then please disregard my answer and go ask your professor

[Rubberman]

Of course, you can also do dynamic_cast<Type&> in which case you must be prepard to catch( bad_cast ). Sometimes books are better than the net for such stuff. Check out Bjarne Stroustrup's "C++ Programming Language". It will set you back about $65-$70 USD on Amazon.com.