Question

我已尝试运行此功能，但打印出circleCounter仅打印0.如果我将计数器代码置于底部的测试器功能下，则可以正常工作。我究竟做错了什么？我错过了什么吗？

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

所以，如果只你的circleCounter仍然给你0，那么你应该知道隐藏你的变量。

private int circleCounter = 0;适用于全球范围。

int circleCounter = 0;适用于您的方法results的本地范围。最本地的范围优先于变量，因此您通过在此处重新声明它来遮蔽全局变量。

只需取出该声明，您的变量就不会被遮蔽。

编辑：这也假设您实际上调用方法。

Answer 2

代码中的main不会调用results（）方法，因此字段的所有默认值都会打印在您的控制台上，即0或0.0（对于double） as main是程序中java的唯一入口点。

为什么我的柜台不起作用？ Java的

2 个答案: