My first question here so please point out my mistakes. And to be honest I couldn’t find any similar questions.
So I am trying to write something very basic and I really can’t figure why I can’t call a method from my Util Class in my Main class.
Util class
private double accumulatedArea;
private double accumulatedCircumference;
public static double getAccumulatedArea(Shape[] shapes) {
double accumulatedArea = 0;
for (Shape s : shapes) {
accumulatedArea = accumulatedArea + s.area();
return accumulatedArea;
}
return accumulatedArea;
}
public static double getAccumulatedCircumference(Shape[] shapes) {
double accumulatedCircumference = 0;
for (Shape q : shapes) {
accumulatedCircumference = accumulatedCircumference + q.circumference();
return accumulatedCircumference;
}
return accumulatedCircumference;
}
public String toString() {
return "Number: ";
}
}
and Main class
public static void main(String[] args) {
Shape[] shapes = new Shape[4];
shapes[0] = new Circle(100);
shapes[1] = new Circle(23);
shapes[2] = new Rectangle(10, 20);
shapes[3] = new Rectangle(8, 12);
System.out.println("Area of the circle 1: " + shapes[0].area() + " and its circumference is: " + shapes[0].circumference());
System.out.println("Area of the circle 2: " + shapes[1].area() + " and its circumference is: " + shapes[1].circumference());
System.out.println("Area of the rectangle 1: " + shapes[2].area() + " and its circumference is: " + shapes[2].circumference());
System.out.println("Area of the rectangle 2: " + shapes[3].area() + " and its circumference is: " + shapes[3].circumference());
//Small test
System.out.println("Number of shapes are in the system: " + shapes.length);
//????? What to do here??
for (int p = 0; p < shapes.length; p++) {
Shape[p].getAccumulatedArea();
}
}
}
How can I call my getAccumulatedArea and getAccumulatedCircumference methods??
Been searching for couple of days now and I really don’t have any idea how.
Just in case there is also 2 Rectangle and Circle classes that I use. They are very similar so I am only putting one.
private double radius;
private double circumference;
private double area;
private ArrayList<Circle> circles;
//throws Exception gives error! learn how to do exceptions!
public Circle(double radius) {
super();
if(radius > 0) {
this.radius = radius;
}
else {
System.out.println("Throw new Exception!!");
}
}
public void setRadius(double radius) throws Exception {
if (radius < 0) {
throw new Exception();
}
else {
this.radius = radius;
}
}
public void setCircumference(double circumference) throws Exception {
if (circumference < 0) {
throw new Exception();
}
else {
this.circumference = circumference;
}
}
public void setArea(double area) {
if (area <= 0) {
System.out.println("Please check your input!");
}
else {
this.area = area;
}
}
public double getRadius() {
return radius;
}
public double getCircumference() throws Exception{
if (radius < 0) {
throw new Exception();
}
else {
return circumference;
}
}
public double getArea() throws Exception{
if (radius < 0) {
throw new Exception();
}
else {
return area;
}
}
@Override
public double circumference() {
return 2 * Math.PI * radius;
}
@Override
public double area() {
return radius * radius * Math.PI;
}
}
The code seems kinda messy but that’s because I’ve been trying everything 🙂 Any advice is welcome. Btw I was using Arraylist but according to some people I know, using Array is much better in this circumstance.
>Solution :
The methods in your Util class are static. A static method should be invoked on the class it is declared as part of. Both of your methods you have declared to take a parameter of type Shape[]. So you should invoke them like so:
Util.getAccumulatedArea(shapes)
…where shapes is a value of type Shape[].