Question

Garbage collector works in following condition:

1.
Employee john = new Employee()
john=null;

2.
Employee c1 =new Employee()
Employee c2 = new Employee()
c1=c2;

3.
new Employee(); //anonymous object

Please create a class /classes in java which contains examples related to above 3 conditons.

Answer 1

In java, when object has no reference or unreferenced (means it is no longer usable) the memory given to these objects can be made avilable or free. and all this is done automatically by Garbage collector in java.

Here is screenshot of Java code:

Here is the Output:

Here is the code:

public class Employee {
    // finalize method is used to perform cleanup activities
    // we can make finalize public also
     protected void finalize()
    {
        System.out.println("Garbage collector collected the object");
    }
    public static void main(String[] args) {
        Employee john = new Employee();
        john=null; //object john has no vlaue so space allocated to it can be freeup
                 
      
        Employee c1 =new Employee();
        Employee c2 = new Employee();
        c1=c2; //now c1 has value of c2 so previous allocated space can be freeup
             
      
        new Employee(); // this anonymous object is of no use so it can also freeup
                      
        System.gc(); //this method is used to invoke the Garbage Collector
    }
}