Is it always possible to automatically delete an object if there are only strong references to it?

Automatic deletion of an object when only strong references to it exist is not always possible. In systems with automatic memory management, such as Android with garbage collection, an object is considered alive if there is at least one strong reference to it. As long as at least one strong reference exists, the object will not be deleted.

However, if all references to the object are weak (WeakReference) or soft (SoftReference), and there are no strong references, the garbage collector may delete the object. Thus, having at least one strong reference guarantees that the object will remain in memory.

Exceptions may include cyclic references, which the garbage collector can detect and clean up, but in this case, all references within the cycle must be strong, and outside the cycle — absent. If the object is referenced by strong references from outside, it will not be deleted.