How does garbage collection work with object references?

Garbage collection works with object references by automatically freeing memory that is no longer referenced by any objects.

Garbage collection is a form of automatic memory management that is used in many modern programming languages. The purpose of garbage collection is to reclaim memory occupied by objects that are no longer in use by the program. It works by keeping track of all the objects that are referenced by other objects. When an object is no longer referenced by any other objects, it is considered "garbage" and its memory can be reclaimed.

In the context of object-oriented programming, an object reference is a link or pointer to an object. When an object is created, a reference to that object is also created. This reference can be used to access the object's properties and methods. If all references to an object are removed, the object becomes inaccessible and can be considered for garbage collection.

The garbage collector, which is part of the runtime environment, periodically checks all object references. It identifies objects that are no longer accessible from the root of the object graph (typically global variables and local variables on the call stack). These objects are marked as garbage. The garbage collector then reclaims the memory occupied by the garbage objects and makes it available for future object allocation.

Garbage collection helps to prevent memory leaks and can simplify memory management in object-oriented programming. However, it can also introduce overhead as the garbage collector requires CPU time to identify garbage objects. Additionally, the timing of garbage collection can be unpredictable, which can lead to performance issues in real-time systems.

In summary, garbage collection works with object references by tracking the accessibility of objects. When an object is no longer referenced by any other objects, it is considered garbage and its memory is automatically reclaimed by the garbage collector. This process helps to ensure efficient use of memory in object-oriented programming.