Dynamic memory allocation

• mechanism to adjust the amount of memory allocated to a program
• need to maintain at least one reference (e.g. pointer) to dynamically allocated memory
• lack of any reference to dynamically allocated memory is known as a memory leak
• dynamically allocated member is typically located outside the object
• not automatically "cleaned up"
• generally a good idea to initialize pointers in the constructor.
• destructor commonly deallocates dynamically created memory.
• destructor is the last function that runs for an object
• Common steps for a dynamically allocated and resizeable array:
1. new - create new array of desired size
2. copy - copy old contents into new array
3. delete - deallocate old array
4. adjust pointers - assign array pointer to newly allocated array

Copying

• shallow vs deep copies, what is the difference?
• copy constructor
• copy assignment operator
• example

More examples

• PFArrayD
• How can PFArrayD be extended to include array resizing?
• BString

Additional Notes

• Assignement 5
• Do not wait till the last minute!
• Design your solution before coding.
• Separate out memory management from the algorithm implementation.
• Restrict new/delete to a select set of functions.
• Make sure every new has a corresponding delete.