I’m stuck on a mock exam question. I created a class called Power which allowed a number to be raised to any power.
The third part of the question asks me to create another class BoundedPower which would extend Power. I was given the MAX-X variable (x cannot exceed this value) and told that the BoundedPower class must: behave like the Power class, use a constructor and use thepowN method.
My code is below, i am not sure what to do to make the BoundedPower class work.
public class Power {
private double x = 0;
Power(double x) {
this.x = x;
}
public double getX() {
return x;
}
public double powN(int n) {
double result = 1.0;
for (int i = 0; i < n; i++) {
result = result * x;
}
return result;
}
public static void main(String[] args) {
Power p = new Power(5.0);
double d = p.powN(3);
System.out.println(d);
}
}
public class BoundedPower extends Power {
public static final double MAX_X = 1000000;
// invariant: x <= MAX_X
Power x;
BoundedPower(double x) {
super(x);
// this.x=x; x is private in Power class
}
public double powN(int n) {
if (x.getX() > MAX_X) {
return 0;
} else {
double result = 1.0;
for (int i = 0; i < n; i++) {
result = result * getX();
}
return result;
}
}
public static void main(String[] args) {
BoundedPower bp = new BoundedPower(5);
double test = bp.powN(4);
System.out.println(test);
}
}
You don’t have to copy your computation formular to the subclass (just call
super.powN(..)). You also don’t need another instance ofPowerwithinBoundedPower.