I have a class A whose objects are created dynamically:
A *object;
object = new A;
there will be many objects of A in an execution.
i have created a method in A to return the address of a particular object depending on the passed id.
A *A::get_obj(int id)
implemetation of get_obj requires itteration so i chose vectors to store the addresses of the objects.
vector<A *> myvector
i think another way to do this is by creating a file & storing the address as a text on a particular line (this will be the id).
this will help me reduce memory usage as i will not create a vector then.
what i dont know is that will this method consume more time than the vector method?
any other option of doing the same is welcome.
Yes, it will consume a lot more time – every lookup will take several thousand times longer. This does not hurt if lookups are rare, but if they are frequent, it could be bad.
How many object are you expecting to manage this way? Are you certain that memory-usage will be a problem?
These are your two options, really. You can either manage the list in memory, or on disk. Depending on your usage scenario, you can combine both methods. You could, for instance, keep frequently used objects in memory, and write infrequently used ones out to disk (this is basically caching).