new & delete operators

Properties of 'new'

• 'new' operator initializes new object. i.e; it first calls the memmory allocation premitive, then call the appropriate constructor of the class. 
• It is type safe. 
• The 'new' operator can be overloaded by a class. 
• 'new' operator never ever returns NULL. Instead, if 'new' operator runs out of memory during new operation, it throws an exception of type bad_alloc. (C's malloc() returns NULL)
• set_new_handler() installs the new handler.
• The placement syntax of the new operator, construct the object at a predetermined position in memory (void* place = (void*) 0xFEEDBABE; Fred* p = new(place) Fred(42, 42);).We should explicitly call the object's destructor after placement syntax.
• If an exception occurs in the constructor during p = new SomeClass(), the sizeof(SomeClass) bytes that were allocated are automatically released back to the heap.

Properties of 'delete'  

• 'delete' is a two-step operation: it first calls the destructor on the object pointer, say p, then it releases the memory pointed to by p using a memory deallocation primitive.
• Calling delete p when p is NULL is safe and is guaranteed to do nothing. 
• Never delete call a pointer twice, Is a DISASTER!. This is likely to corrupt the heap and its list of free memory. 
• delete[] p is for deleting an array of things. 
• Its legal for a member function to say delete this, but be careful.  
• The realloc move data to a new location, it uses a bitwise copy

Difference between 'operator new' and the 'new' operator?

• The term "operator new" is used incase when u are overloading the global "new" operator. 
• The term "new operator" is used in case of dynamic allocation of memory.When a variable is allocated memory dynamically the new operator is used.