如何更改在Java中使用我的2-D数组的方法

Question

I have written a program using 2 separate arrays but want to combine the arrays (velocity and degrees) into one single multidimensional array called distance. I have never used 2-D arrays before and I am sure my code may be hard to understand.

I have rewritten most of the program but I am getting held up in the method "calcDistance". I tried to rewrite the method but it just turned into a big mess.

double [][] distance;

Catapult(double[][] d){
   distance = d;
}

public double [][] calcDistance(){

    double [][] total = {{0,0,0,0,0,0,0} , {0,0,0,0,0,0,0}};

    for (int row = 0; row < distance.length; row++){

        for (int column = 0; column < distance.length; column++){

        total[row][column] = (Math.pow(distance[column]/2.237, 2) * Math.sin(2 * Math.toRadians(distance[column]))/9.8);

       }
    }

    return total;
}

I get a bad operand error when dividing by 2.237 and an incompatible types error when using distance[column]. Now my two problems are

1) How can I fix this method and what did I initially do wrong to cause the error

2) How can I implement both parts of my multi-d array distance in the method because as of right now it only runs through the columns of one row in "distance"

Answer 1

I really recommand you to use iterator since it make everything easier:

public class Catapult {
    double [][] distance;

    Catapult(double[][] d){
       distance = d;
    }

    public double [][] calcDistance(){

        double [][] total = new double[2][7];

        int i=0;

        for (double[] row : distance) {

            int j=0;

            for (double value : row) {

                total[i][j] = (Math.pow(value/2.237, 2) * Math.sin(2 * Math.toRadians(value))/9.8);

                ++j;

            }

            ++i;

        }


        return total;
    }
}