In what situation factory design patterns,DAO design
patterns,singleton design patterns should be applied.?
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Answer Posted / rajan
Unlike constructors, factory methods are not required to
create a new object each time they are invoked. Factory
methods can encapsulate the logic required to return a
singleton instance of the class requested, or they can
return an instance of the requested class from a pool of
instances.
Factory methods can return any subtype of the type
requested, and can require that clients refer to the
returned object by its interface, rather than the
implementation class. This enables an API to return objects
without making their classes public.
The class for the object returned by a factory method need
not even exist at the time the factory method is written.
This is one of the classic benefits of polymorphism: "old
code uses new code," which means that new classes can be
added, and their instances returned by the factory method,
without changing any of the existing code.
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cout< can inline function declare in private part of class? What is cohesion in oop? write a code for this:trailer recordId contains a value
other than 99, then the file must error with the
reason ‘Invalid RECORD_ID’(User Defined Exception). What are functions in oop? What is solid in oops? Why is oop better than procedural? Prepare me a program for the animation of train How do you define a class in oop? What are the benefits of interface? What is destructor example? What are the benefits of oop? What is a class and object? Question In a class, there is a reference or pointer of an
object of
another class embedded, and the memory is either allocated
or assigned to the new object created for this class. In
the constructor, parameters are passed to initialize the
data members and the embedded object reference to get
inialized. What measures or design change should be advised
for proper destruction and avioding memory leaks, getting
pointers dangling for the embedded object memory
allocation? Please suggest.
Question Submitted By :: Sunil Kumar
I also faced this Question!! Rank Answer Posted By
Re: In a class, there is a reference or pointer of an
object of another class embedded, and the memory is either
allocated or assigned to the new object created for this
class. In the constructor, parameters are passed to
initialize the data members and the embedded object
reference to get inialized. What measures or design change
should be advised for proper destruction and avioding
memory leaks, getting pointers dangling for the embedded
object memory allocation? Please suggest.
Answer
# 1 use copy constructors
0 Shanthila
There is something to be taken care in destructor, in copy
constructor, suppose the memory is assigned to the embedded
member object pointer with the parameter passed value, but
if some other objects of different class also are pointing
to this memory, then if some one deletes the object then
this class member pointer object will become dangling, or
if the object is not deleted properly then there will be
memory leak. Please suggest the design change required to
handle or avoid this situation What are the 4 pillars of oop?
