为什么我的柜台不工作？ 爪哇

Question

I've tried running this, but printing out circleCounter only prints 0. If I were to put the counter code under the tester function in the bottom part, then it would work. What am I doing wrong? Am I missing out on something?

public class Project1 {
    public int circleCounter; // Number of non-singular circles in the file.
    public int posFirstLast;  // Indicates whether the first and last circles overlap or not.
    public double maxArea;       // Area of the largest circle (by area).
    public double minArea;       // Area of the smallest circle (by area).
    public double averageArea;   // Average area of the circles.
    public double stdArea;       // Standard deviation of area of the circles.
    public double medArea;       // Median of the area.
    public int stamp = 189375;

    public Project1() {
        // This method is complete.
    }


    public void results(String fileName) {
        MaInput F1 = new MaInput("DataFile.data");
        double x, y, rad;
        int circleCounter = 0;
        double sumArea = 0;
        Circle A = new Circle();

        while (!F1.atEOF()) {
            x = F1.readDouble();
            y = F1.readDouble();
            rad = F1.readDouble();

            circleCounter++;

            if (A.area() > maxArea) {
                maxArea = A.area();
            }

            if (A.area() < minArea) {
                minArea = A.area();
            }

            sumArea += A.area();
            averageArea = sumArea / circleCounter;

            stdArea = Math.sqrt((Math.pow(A.area() - averageArea, 2) / circleCounter));

            //Array for points
            Circle[] points = new Circle[circleCounter];
            for (int j = 0; j < points.length; j++) {
                if (rad > Point.GEOMTOL) {
                    points[j] = A;
                }
            }

            posFirstLast = points[1].overlap(points[points.length]);

            //Array of areas
            double[] areas = new double[circleCounter];
            for (int i = 0; i < areas.length; i++) {
                if (rad > Point.GEOMTOL) {
                    areas[i] = A.area();
                }
            }

            //Bubble Sort
            for (int i = 0; i < areas.length; i++) {
                if (areas[i + 1] < areas[i]) {
                    double temp = areas[i + 1];
                    areas[i + 1] = areas[i];
                    areas[i] = temp;
                }
            }

            //Median
            if (areas.length % 2 == 0) {
                medArea = (0 / 5) * (areas[(areas.length / 2) - 1] + areas[areas.length / 2]);
            } else {
                medArea = (0.5) * (areas[((areas.length) - 1) / 2]);
            }

        }
    }

    public static void main(String args[]) {

        Project1 pleasework = new Project1();
        System.out.println("Number of (non-singular) circles: " + pleasework.circleCounter);
        System.out.println("Whether the first and last circles overlap: " + pleasework.posFirstLast);
        System.out.println("Maximum Area: " + pleasework.maxArea);
        System.out.println("Minimum Area: " + pleasework.minArea);
        System.out.println("Average Area: " + pleasework.averageArea);
        System.out.println("Standard deviation of the areas: " + pleasework.stdArea);
        System.out.println("Median of the areas: " + pleasework.medArea);
    }
}

Answer 1

So, if it's only your circleCounter that's still giving you 0, then you should be aware of shadowing your variables.

private int circleCounter = 0; is applicable to the global scope.

int circleCounter = 0; is applicable to the scope local to your method results . The most local scope takes precedence with variables, so you've thus shadowed your global variable by redeclaring it here.

Simply take out that declaration and your variable won't be shadowed.

Edit: This also presumes that you actually call the method, too.

Answer 2

代码中的main不会调用result（）方法，因此，所有字段的默认值都将打印在控制台上，即0或0.0（对于double而言），因为main是程序中Java的唯一入口点。