Constructors

[Ranjith. B]

can anyone tell me the reason why we have to use the Super() in first line of the constructor block while calling the super class constructor?Is there any special reason for that?Please explain me.

[Bosun Bello]

Yes, so that your superclass can get initialized properly, if there is any initialization that needs to be done. Assuming that your class depends on the superclass being in a specific state, the call to super will force that initialization to be performed.

[Max Habibi]

You don't have to call super: the default super gets called automatically. The reason you might want to, however, is for times when you need a constructor other then the default constructor.
In the example below, the object kid_1 uses the default call, but the onject kid_2 uses an overloaded constructor.

public class Parent {
public Parent(){
System.out.println("Parent");
}
public Parent(String name ){
System.out.println("Parent named " + name);
}
}

and

public class Child extends Parent {
public Child(){
System.out.println("Child");
}
public Child(String parentName){
super(parentName);
System.out.println("Child with named parent");
}
public static void main(String args[]){
//calls default onstructor
Child kid_1 = new Child();
//calls overloaded cnstructor
Child kid_2 = new Child("mike");
}
}

HTH,
M

[Frank Carver]

And you definately need to call super(...) if the parent class has no "()" constructor.

[Ranjith bala]

Thanks for the reply.NOw i got cleared.