What will be the output when we add elements in collection of ArrayList in java?

Problem statement: In given java code, can you please let me know, what will be the output.

1. import java.util.ArrayList;
2. class A {}
3. class B {}
4. class C {}
5. public class Test {
6. public static void main(String[] args) {
7. ArrayList list = new ArrayList();
8. list.add(new A());
9. list.add(new B());
10. list.add(new C());
11.   list.add(new A());
12. System.out.println(list);
13.   System.out.println("Size: " + list.size());
14. }
15. }

Answer:
[com.practice.core.A@15db9742, com.practice.core.B@6d06d69c, com.practice.core.C@7852e922, com.practice.core.A@4e25154f]
Size: 4

Note: fully_qualified_class_name@hashcode_value