Question

I am getting an error at linen 57 and can't figure out how to fix it.

// Java program to read a CSV file and display the min, max, and average of numbers in it.
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Arrays;
import java.util.Scanner;

public class Main {

    // method to determine and return the minimum number from the array
    public static int minimum(int numbers[])
    {
        int minIdx = 0;
        for(int i=1;i<numbers.length;i++)
        {
            if((minIdx == -1) || (numbers[i] < numbers[minIdx]))
                minIdx = i;
        }
     
        return numbers[minIdx];
    }

    // method to determine and return the maximum number from the array
    public static int maximum(int numbers[])
    {
        int maxIdx = 0;
        for(int i=1;i<numbers.length;i++)
        {
            if((maxIdx == -1) || (numbers[i] > numbers[maxIdx]))
                maxIdx = i;
        }
     
        return numbers[maxIdx];
    }

    // method to calculate and return the average of all numbers from the array
    public static double average(int numbers[])
    {
        int total = 0;
        for(int i=0;i<numbers.length;i++)
            total += numbers[i];
        return(((double)total)/numbers.length);
    }

   public static void main(String[] args) throws FileNotFoundException {

        Scanner fileScan = new Scanner(new File("C:\\Users\\useracct\\eclipse-workspace\\Group4 Final\\src\\numbers.csv")); // open the CSV file, provide full path to file
        int numbers[] = null;
        fileScan.useDelimiter(","); // use the delimiter , to separate the data in the file since it is a CSV file
        // read till the end of file
        while(fileScan.hasNext())
        {
            //    check if array is not created
            if(numbers == null)
                numbers = new int[1]; // then create it with 1 element
            else
                numbers = Arrays.copyOf(numbers, numbers.length+1); // expand the array by 1 size
            numbers[numbers.length-1] = fileScan.nextInt(); // populate the array with the number read
        }
     
        fileScan.close(); // close the file
        // if file wasn't empty
        if(numbers.length > 0)
        {
            // display the numbers, minimum, maximum and average of numbers
            System.out.println("Number(s) read from file : ");
            for(int i=0;i<numbers.length;i++)
            {
                System.out.println(numbers[i]+" ");
            }
            System.out.println();
            System.out.println("Minimum number : "+minimum(numbers));
            System.out.println("Maximum number : "+maximum(numbers));
            System.out.println("Average number : "+average(numbers));
        }

    }

}

//end of program

Answer 1

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Arrays;
import java.util.Scanner;

public class Main {

    // method to determine and return the minimum number from the array
    public static int minimum(int numbers[]) {
        int minIdx = 0;
        for (int i = 1; i < numbers.length; i++) {
            if ((minIdx == -1) || (numbers[i] < numbers[minIdx]))
                minIdx = i;
        }

        return numbers[minIdx];
    }

    // method to determine and return the maximum number from the array
    public static int maximum(int numbers[]) {
        int maxIdx = 0;
        for (int i = 1; i < numbers.length; i++) {
            if ((maxIdx == -1) || (numbers[i] > numbers[maxIdx]))
                maxIdx = i;
        }

        return numbers[maxIdx];
    }

    // method to calculate and return the average of all numbers from the array
    public static double average(int numbers[]) {
        int total = 0;
        for (int i = 0; i < numbers.length; i++)
            total += numbers[i];
        return (((double) total) / numbers.length);
    }

    public static void main(String[] args) throws FileNotFoundException {

        Scanner fileScan = new Scanner(new File("C:\\Users\\useracct\\eclipse-workspace\\Group4 Final\\src\\numbers.csv")); // open the CSV file, provide full path to file
        int numbers[] = null;
        fileScan.useDelimiter(","); // use the delimiter , to separate the data in the file since it is a CSV file
        // read till the end of file
        while (fileScan.hasNext()) {
            //    check if array is not created
            if (numbers == null)
                numbers = new int[1]; // then create it with 1 element
            else
                numbers = Arrays.copyOf(numbers, numbers.length + 1); // expand the array by 1 size
            numbers[numbers.length - 1] = fileScan.nextInt(); // populate the array with the number read
        }

        fileScan.close(); // close the file
        // if file wasn't empty
        if (numbers != null) {  // Error here.  numbers != null should be used here to check if there are numbers in array
            // display the numbers, minimum, maximum and average of numbers
            System.out.println("Number(s) read from file : ");
            for (int i = 0; i < numbers.length; i++) {
                System.out.println(numbers[i] + " ");
            }
            System.out.println();
            System.out.println("Minimum number : " + minimum(numbers));
            System.out.println("Maximum number : " + maximum(numbers));
            System.out.println("Average number : " + average(numbers));
        }

    }
}