The code given below shows a Stackoverflow error when run.But if I make another class CarChange to create objects of Car ,it runs sucessfully. I am a beginner ,doing this code to understand the importance of upcasting in java.
public class Car {
int i;
Car[] c=new Car[2];
Car() {
c[0] = new Polo();
i=0;
}
void drive(){
c[i].testdrive(); //the overloaded method in subclasses polo and swift
}
void change() {
if(i==0) {
i++;
c[i] = new Swift();
}
}
public void testdrive() {
//overloaded method in subclasses polo and swift
System.out.println(" test drive car");
}
//class Tester {
//main
Car c= new Car();
c.drive();
c.change();
c.drive();
A stackoverflow usually means you have an infinite loop.
The reason you're receiving this is because you're calling drive from the testdrive method and in that method you're calling drive again.