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Thread: Why cant I call on the array I returned in the main method?

  1. #1
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    Default Why cant I call on the array I returned in the main method?

    //matrix1
       double[][] matrix1 = {{1, 2, 3},{4, 5, 6},{7, 8, 9}};      
     
    //matrix2
       double[][] matrix2 = {{0, 2, 4},{1, 4.5, 2.2},{1.1, 4.3, 5.2}};   
     
       addMatrix(matrix1, matrix2);
     
       printArrays(matrix1, matrix2, result, '+');
     
     
      }//end of main
     
        public static double[][] addMatrix(double[][] a, double[][] b){
     
    double[][] result = {{a[0][0]+b[0][0], a[0][1]+b[0][1], a[0][2]+b[0][2]},
        {a[1][0]+b[1][0], a[1][1]+b[1][1], a[1][2]+b[1][2]},
        {a[2][0]+b[2][0], a[2][1]+b[2][1], a[2][2]+b[2][2]}};
     
    return result;
    }
     
        public static void printArrays(double[][] m1, double[][] m2, double[][] m3, char op)
    {
    for (int i = 0; i < m1.length; i++) {
    for (int j = 0; j < m1[0].length; j++) {
    System.out.print(" " + m1[i][j]);
    }
    if (i == m1.length / 2)
    System.out.print(" " + op + " ");
    else {
    System.out.print(" ");
    }
    for (int j = 0; j < m2[0].length; j++) {
    System.out.print(" " + m2[i][j]);
    }
    if (i == m1.length / 2)
    System.out.print(" = ");
    else {
    System.out.print(" ");
    }
    for (int j = 0; j < m3[0].length; j++) {
    System.out.print(" " + m3[i][j]);
    }
    System.out.println();
    }
    } 
    //    public static void printArrays(double[][] a) {                        
    //        for(int row = 0; row < a.length; row++){
    //        for (int col = 0; col < a[row].length; col++) {
    //            
    //            System.out.print(a[row][col] + " ");
    //        }//end of inner for loop
    //        System.out.println("");
    //        
    //}//end of outer for loop
    //    }//end of printArrays
     
        }//end of class


  2. #2
    Administrator copeg's Avatar
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    Default Re: Why cant I call on the array I returned in the main method?

    See the link in my signature entitled "Getting Help". I might be the only one, but have no clue what you are asking - the guidelines in that link will help you get your point/question across.

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    Default Re: Why cant I call on the array I returned in the main method?

    In my method addMatrix I return the array result. I then try to call it in my main method to print out, however it gives me an error saying it cannot find the variable. Since I returned it shouldnt I be able to call it?

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    Default Re: Why cant I call on the array I returned in the main method?

    Quote Originally Posted by ColeTrain View Post
    In my method addMatrix I return the array result. I then try to call it in my main method to print out, however it gives me an error saying it cannot find the variable. Since I returned it shouldnt I be able to call it?
    The method may have returned the matrix, but when you call the method you do not actually assign a reference to the returned value - the reference within the method being out of scope once the method returns. You must first assign a reference value to the returned value of the method before you can use it.

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