Question

我必须创建一个类来计算类的2个给定点之间的距离。教师向我们提供了所有必要代码的上半部分而没有修改，我正在创建类部分的问题。这就是我到目前为止......

class Point{
int x;
int y;

public Point(){
    this.x = 0;
    this.y = 0;

}

public Point(int x, int y){
    this.x = x;
    this.y = y;
}
 public double distance(int x, int y) {
    double d = Math.sqrt( Math.pow(x2-x1, 2) + Math.pow(y2-y1, 2) );
    return distance;
}
}

作业的上半部分如下所示：

import java.util.Scanner;


class Assignment4{
public static void main(String[] args){
    // first and second points
    Point first, second;

    // try parsing points from command line args
    if(args.length==4){
        // new Point(int x, int y) creates a new Point located at position (x,y)
        first = new Point(Integer.valueOf(args[0]), Integer.valueOf(args[1]));
        second = new Point(Integer.valueOf(args[2]), Integer.valueOf(args[3]));
    }

    // if not specified as argument, get points from user
    else{
        Scanner input = new Scanner(System.in);

        System.out.println("Enter first point: ");
        first = new Point(input.nextInt(),input.nextInt());

        System.out.println("Enter second point: ");
        second = new Point(input.nextInt(),input.nextInt());
    }

    //calculate distance
    //double d = Math.sqrt( Math.pow(x2-x1, 2) + Math.pow(y2-y1, 2) );
    double d = first.distance(second.x, second.y);

    System.out.println("Distance between " + 
        "(" + first.x + "," + first.y + ")" + 
        " and " + 
        "(" + second.x + "," + second.y + ")" + 
        " is " + d);
    System.out.println();
}
}

当我尝试编译程序时，它会说“无法找到符号”，指的是x2，x1，y2，y1和distance。

Answer 1

这里：

class Point{
     int x;
     int y;

     .....
     .....

     public double distance(int x, int y) {
        double d = Math.sqrt( Math.pow(x2-x1, 2) + Math.pow(y2-y1, 2) );  //ERROR IN THIS LINE
        return distance; //ERROR HERE TOO...(2)
     }
}

在类或方法参数中没有定义x1，x2，y1，y2。

使用以下行交换它：

double d = Math.sqrt（Math.pow（this.x-x，2）+ Math.pow（this.y-y，2））;

（2）错误2与此行交换：

返回d;

计算2个给定点之间的距离

1 个答案: