How to declare deconstructor?

HelloWorld · #1 (**permalink**) 10-06-2007, 10:28 AM

I'm just wondering since I never use it...

I start to ask this question because I realized on how important it is XD I heard that it may cause Memory Leaks..? Thx

Bench · #2 (**permalink**) 10-07-2007, 06:31 AM

No, the lack of a destructor doesn't cause memory leaks. Forgetting to delete memory causes memory leaks. A destructor is sometimes useful if you have new'ed memory somewhere and you wish for your class to clean up after itself. In this case, writing a destructor can help, in most cases, you'll not need to write one.

The syntax is similar to a constructor (Except that it must take 0 arguments and cannot be overloaded), but with the bit complement operator in front

Code:

class myclass
{
    ~myclass()
    {
        //delete etc.
    }
};

HelloWorld · #3 (**permalink**) 10-07-2007, 11:31 AM

How do you delete memory that's been used in C++? Each time we're using pointer, don't we use memory...? As far as I know, I never done anything to delete them..

ccoonen · #4 (**permalink**) 10-07-2007, 02:29 PM

Essentially you just want to make it Available for the Garbage Collector to come get it - like unreference it from items. If it has no references and isn't being used, then the GC can come "collect" that memory. You can also force it (GC.Collect) but generally it's enough to make it available for pickup and it will be dealt with accordingly

Bench · #5 (**permalink**) 10-09-2007, 05:05 AM

Quote:

Originally Posted by ccoonen

Essentially you just want to make it Available for the Garbage Collector to come get it - like unreference it from items. If it has no references and isn't being used, then the GC can come "collect" that memory. You can also force it (GC.Collect) but generally it's enough to make it available for pickup and it will be dealt with accordingly

C++ hasn't got a garbage collector. perhaps you're confusing it with one of the managed microsoft languages?

to clean up memory allocated with new, use the delete keyword. If you forget to delete, this is when you get memory leaks.

Code:

//Allocating & deallocating space for a single object
int* foo = new int;
delete foo;

Code:

//Allocating & deallocating space for an array of 20 ints
int* bar = new int[20];
delete [] bar;

ccoonen · #6 (**permalink**) 10-09-2007, 11:41 AM

Sorry, I thought when we were talking about VC++ which has the Finalize method to destruct

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

The Following User Says Thank You to Bench For This Useful Post:
HelloWorld (10-07-2007)

The Following User Says Thank You to ccoonen For This Useful Post:
HelloWorld (10-07-2007)