阵列打印不正确

Question

I am working on a program in which I am reading a list of Celsius temperatures from a file, loading them into an array, and eventually loading another array with the corresponding Fahrenheit temperatures for each Celsius temperature.

When attempting to print the fahrArray, rather than displaying actual temperatures which were converted to Fahrenheit to Celsius, I am given this

[D@3d3b10b1>

Here is the code that I have so far.

import java.util.Scanner;
import java.io.*;

public class BonusLab {
  public static void main(String[] args) throws IOException {

    createdBy();

    double[] celArray = loadCelArray();

    printArray(celArray);

    double[] fahrArray = loadFahrArray(celArray);

  } // end main

  public static void createdBy() {
    System.out.println("Program created by-Beth Tanner");
  } // end createdBy

  public static double[] loadCelArray() throws IOException {
    Scanner fin = new Scanner(new File("weather.txt"));

    int x = fin.nextInt();

    double[] celArray= new double[x];

    for(int i = 0; i < celArray.length; i++)
      celArray[i] = fin.nextDouble();

    return celArray;
  } // end loadCelArray

  public static void printArray(double[] celArray) {
    for(int i = 0; i < celArray.length; i++)
    System.out.print(celArray[i] + " ");
  } // end printArray

  public static double[] loadFahrArray(double[] celArray) throws      IOException {
    Scanner fin = new Scanner(new File("weather.txt"));

double celsius = 

int x = fin.nextInt();

double[] fahrArray = new double[x];
for(int i = 0; i < fahrArray.length; i++) 
  fahrArray[i] = (9 / 5) * celsius + 32;

return fahrArray;
  } // end loadFahrArray

} // end class

Any help or suggestions would be greatly appreciated.

Answer 1

If I understood your code right, I think you should change this code

for(int i = 0; i < fahrArray.length; i++) 
    fahrArray[i] = (9 / 5) * celsius + 32;

to

for(int i = 0; i < fahrArray.length; i++) 
    fahrArray[i] = (9 / 5.0) * celArray[i] + 32;

You are trying to access celArray[i] at a position where i is not defined. In the for-loop i is defined and should be at the same position.

Another soluion is, that you can leave out the second scanning of the file, because u have already loaded the values. So it will be enough to loop through calArray.

Edit: user3008950 now provided the second possibility I wrote about.

Answer 2

public static double[] loadFahrArray(double[] celArray){
    double[] result=null;
    if(celArray!=null){
        result=new double[celArray.length];
        for(int i = 0; i < celArray.length; i++){ 
            result[i] = (9 / 5.0) * celArray[i] + 32;
        }
    }
    return result;
}