How to find an object if there are no references to it?

The Garbage Collector detects objects without references for subsequent memory release.

It works by tracking the accessibility of objects from "roots" such as:

• Local variables of the current thread.
• Static fields of classes.
• References from JNI (Java Native Interface).
• Objects used by the garbage collector for internal purposes.

The process generally looks like this:

1. Marking: Starting from the roots, all objects that are referenced are recursively marked. This creates a graph of accessible objects.
2. Sweeping: The heap is scanned. All objects that were not marked in step 1 (inaccessible) are considered garbage and their memory is freed.
3. Compaction (optional): After freeing memory, objects may be moved to defragment the heap.

An example of a hypothetical object without references:

// Create an object
MyObject obj = new MyObject();

// ... some logic ...

// Remove the last reference to the object
obj = null; // Now, there are no references to the original MyObject

// The garbage collector can now collect it

Objects without references become candidates for collection, but there is no guarantee that the garbage collector will run immediately.