java - 如何在Java类方法中访问私有(private)变量

Question

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已关闭 10 年前。

我正在尝试在我的方法 x 中访问私有(private)变量 ( distanceFromPoint )但似乎不起作用。我怎样才能访问它？我的方法返回 0.0无论其他值如何，始终如此。

代码

public class Pointdeclare {
    private static int x;
    private static int y;

    Pointdeclare (int x_ , int y_ ){
        this.x = x_;
        this.y = y_;
    }

    int getX(){
        return x;
    }

    int getY(){
        return y;
    }

    static double distanceFromZero (){
        return Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));
    }

    double distanceFromPoint(Pointdeclare point){
        int distX = point.getX()- this.x;
        int distY = point.getY()- this.y;

        return (double) Math.sqrt(Math.pow(distX, 2) + Math.pow(distY, 2));
    }
}

主类

public class main {
    static Pointdeclare p1 = new Pointdeclare(6, 7);
    static Pointdeclare p2 = new Pointdeclare(3, 7);

    public static void main (String[] args){
        System.out.println(p2.distanceFromZero());

        System.out.print(p1.distanceFromPoint(p2));
    }
}

Answer 1

这对你来说会更好:

package cruft;

/**
 * Point2 description here
 * @author Michael
 * @link http://stackoverflow.com/questions/14087002/how-to-access-private-variables-in-a-java-class-method
 * @since 12/29/12 6:52 PM
 */
public class Point2 {

    private int x;
    private int y;

    Point2(int x_, int y_) {
        this.x = x_;
        this.y = y_;
    }

    int getX() {
        return x;
    }

    int getY() {
        return y;
    }

    double distanceFromZero() {
        return distanceFromPoint(new Point2(0, 0));
    }

    double distanceFromPoint(Point2 point) {
        int distX = point.getX()-this.x;
        int distY = point.getY()-this.y;

        return (double) Math.sqrt(Math.pow(distX, 2)+Math.pow(distY, 2));
    }


    public static void main(String[] args) {
        Point2 p1 = new Point2(6, 7);
        Point2 p2 = new Point2(3, 7);
        System.out.println(p2.distanceFromZero());
        System.out.print(p1.distanceFromPoint(p2));
    }
}