package arrayList;
import abstractClasses.Employee;
import java.util.ArrayList;
public class Test {
    public static void main(String[] args) {
         var staff = new ArrayList<>();
         staff.add(new Employee("111",2,2,2,2));
         Employee e = (Employee) staff.get(0);
         System.out.println("staff="+staff);
         System.out.println("e="+e);
         System.out.println(staff.get(0));
         staff.set(0,4);
         System.out.println(staff.get(0));
         
    }
}
输出
:
staff=[abstractClasses.Employee@3d075dc0]
e=abstractClasses.Employee@3d075dc0
abstractClasses.Employee@3d075dc0
4
Process finished with exit code 0