copying objects

Question 1

reference copy

Answer 1

the new object in the stack references the object in the heap and its attributes

Question 2

shallow copy

Answer 2

the new object in the stack references an new object in the heap, but its references point to the original objects attributes

Question 3

deep copy

Answer 3

the new object in the stack references a completely new object with a new copy of the attributes

Question 4

when to use reference…

Answer 4

pros: fasted, least amount of space used
cons: if class is mutable, aliasing must be avoided (need true copies to prevent privacy leaks and modifications from outside)

Question 5

when to use shallow…

Answer 5

pros: faster than deep copy, less space used than deep copy
cons: still has aliases (bad, only if the class is mutable)

Question 6

when to use deep…

Answer 6

pros: no aliasing (necessary for mutable classes)
cons: slowest, takes up the most space