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Thread: Creating methods with Arrays

  1. #1
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    Default Creating methods with Arrays

    I'm trying to make my program write to a file using two methods. It compiles with no errors, but when the file that it wrote to is opened, only coordinates with (0,0) are printed. Its supposed to print 10000 random coordinated from the array. Why does it only print out (0,0) coordinates? Also did I place my return statement in the correct place?

    import java.io.*;
     
    public class program
    {
      public static void main (String [] args) throws IOException
      {
     
        int points = 10000, dimension = 2, lengthA = 100;//int variables are declared and initialized
     
        PrintWriter fileOut = new PrintWriter (new FileWriter ("arrayPoints.txt"));
     
        double length [] = new double [dimension];//array for length is declared
        double coordinate [][] = new double [points][dimension];//coordinate array is declared
     
        for (int i = 0; i < points; i++){
          fileOut.println(java.util.Arrays.toString(coordinate[i]));
                          }
          fileOut.close();//writes to file
     
      }//end main method
     
        public static double writeTofile (double length[], double coordinate[][], int points, int dimension, int lengthA)
        {
          int x = 0, y = 0;
          for(int z = 0; z < dimension; z++){//fills the length array with the the set value of lengthA
          length[z] = lengthA;
          }
     
        for(x = 0; x < points; x++){//runs 1000 times to print 1000 data points
          for (y = 0; y < dimension; y++){//runs 2 times to print an x and y coordinate
            coordinate [x][y]= (2 *Math.random() - 1) * length[y];// finds a random number in the range and assiigns it to the coordinate array
          }//end for
        }//end for
        return coordinate[x][y];
      }//main method
    }//program


  2. #2
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    Default Re: Creating methods with Arrays

    You never ever call the writeToFile method

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    Default Re: Creating methods with Arrays

    I've change it and called it herre:

    for (int i = 0; i < points; i++){
          fileOut.println(writeTofile(coordinate[i]));
                          }
          fileOut.close();//writes to file

    however when I compile it it gives me the error

    writeTofile(double[],double[][],int,int,int) in program cannot be applied to (double[])

  4. #4
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    Default Re: Creating methods with Arrays

    The error means you can not call a method with the single parameter of type double[] because the method requires the 5 parameters listed in the error message. (The same 5 the the method is declared with)

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    Default Re: Creating methods with Arrays

    Creating different methods with Arrays

    Duplicate post
    Improving the world one idiot at a time!

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