How is automatic memory cleanup implemented in Dart?

In Dart, automatic memory management is implemented using a garbage collector, which operates based on reference counting and reachability tracing of objects.

When an object is no longer reachable from root references (such as call stacks or global variables), the garbage collector frees the memory occupied by that object. Dart uses a generational garbage collection model, where objects are divided into young and old generations, which increases the efficiency of cleanup.

For developers, this means there is no need to manually free memory — the garbage collector automatically manages the lifecycle of objects, simplifying development and reducing the likelihood of memory leaks.