C++ delete - It deletes my objects but I can still access the data?

Question

I have written a simple, working tetris game with each block as an instance of a class singleblock.

class SingleBlock
{
    public:
    SingleBlock(int, int)         


        

Answer 1

Delete doesn't delete anything -- it just marks the memory as "being free for reuse". Until some other allocation call reserves and fills that space it will have the old data. However, relying on that is a big no-no, basically if you delete something forget about it.

One of the practices in this regard that is often encountered in libraries is a Delete function:

template< class T > void Delete( T*& pointer )
{
    delete pointer;
    pointer = NULL;
}

This prevents us from accidentally accessing invalid memory.

Note that it is perfectly okay to call delete NULL;.