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Q) What is the practical need of calling sub class constructor from within the sub class constructor explicitly? Give an example.





A)
-> to initialize the private variables of super class that belong to subclass object we need to call explicitly super class parameterized constructor from within subclass constructor.
class person
{
       private int age;
       person(int a)
       {
              age=a;
       }
       protected voiddisplaypersondetails()
       {
              System.out.println("age :"+age);
       }
}
class Employeeone extends person
{
       float salary;
       Employeeone(float sal, int a)
       {
              super(a);// should be the first statement
              salary=sal;
       }
       voiddisplayEmployeedetails()
       {
              System.out.println("salary Rs :"+salary);
              displaypersondetails();
       }
}

classexplicitconstructorcalling {
      
       public static void main(String[] args) {
              Employeeone explicit = new Employeeone(2000,45);
              explicit.displayEmployeedetails();
       }

}

Output:

salary Rs :2000.0
age :45

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