procedure FreeAndNil ( var ObjectReference ) ;
Description
The FreeAndNil procedure frees up the memory used by an object, and sets the object reference to nil.
It actually does this in reverse order - first dereferencing the object before deallocating the memory. This is a very clean way of freeing resources.
Related commands
FreeMem Free memory storage used by a variable
GetMem Get a specified number of storage bytes
Nil A pointer value that is defined as undetermined
Null A variable that has no value
Example code : Free and nil an object, and then try to do this again
var
myList : TList;
begin
// Create the list object
myList := TList.Create;
// And now free and nil this object
FreeAndNil(myList);
// We can safely do this twice - it ignores nil objects
FreeAndNil(myList);
end;
Show full unit code
No exception occurs - the second FreeAndNil does nothing.