Can you explain how the garbage collector works in programming languages?

Garbage Collector (GC) is an automatic memory management mechanism that frees memory occupied by objects that are no longer used by the program.

Working principle:

1. Reference tracking: GC determines which objects are accessible (have references from active code) and which are not.
2. Garbage identification: Objects with no references are considered garbage and are subject to deletion.
3. Memory freeing: GC releases the memory occupied by such objects so it can be reused.

In Flutter (Dart), the garbage collector is based on reference counting and periodic cleanup. It runs in the background and aims to minimize pauses in the application's operation.

Example:

class MyClass {
  String data;
  MyClass(this.data);
}

void main() {
  MyClass obj = MyClass('Hello');
  obj = null; // Now the MyClass object is inaccessible and can be collected by GC
}

When obj becomes null, the MyClass object becomes unreachable and will be removed by the garbage collector.