Question

我需要使用.txt文件从文本文件中执行以下代码。我在使用文件中的扫描仪时遇到问题。 b.txt中包含以下文字输入：

40.3 35.8 29.6 45 17.8 19.2 38.6 31.5 27.8 39.9 ......

有人可以帮我解决这个问题吗？

  import java.util.*;
  public class arrayLabFirst
  {

  public static void main(String[] args)
  {
  double[ ] temperatures = new double[10];
  Scanner inFile = new Scanner(new File(“b.txt”)); 

  temeratures[]=infile.hasNext();


  for (int index = 0; index < temperatures.length; index++)
  temperatures[index] = input.nextDouble();

  printArray(temperatures);
  System.out.println("The average of the temperatures entered is: " + arrayAverage(temperatures));
  System.out.println("The greatest temperature is: " + greatest(temperatures));
  System.out.println("The lowest temperature is: " + lowest(temperatures));
  }
  public static void printArray(double[] temperatures)
  {
  for (int i = 0; i < temperatures.length; i++)
  System.out.println(temperatures[i]);
  }
  public static double arrayAverage(double[] temperatures)
  {
  double sum = 0;
  for (int i = 0; i < temperatures.length; i++)
  sum += temperatures[i];
  return sum/temperatures.length;
  }
  public static void countDays(double[] temperatures)
  {
  int aboveCount = 0;
  int belowCount = 0;
  for (int i = 0; i < temperatures.length; i++)
  {
  if (i > 32)
    aboveCount++;
  else
    belowCount++;
  }
 System.out.println("number of days above freezing: " + aboveCount);
 System.out.println("number of days below freezing: " + belowCount);
 }
public static double greatest(double[] temperatures)
{
int maxIndex = 0;
for (int index = 1; index < temperatures.length; index++)
  if (temperatures[maxIndex] < temperatures[index])
  maxIndex = index;

return temperatures[maxIndex];
}
public static double lowest(double[] temperatures)
{
  int minIndex = 0;
  for (int index = 1; index < temperatures.length; index++)
  if (temperatures[minIndex] > temperatures[index])
  minIndex = index;

  return temperatures[minIndex];
}
}

Answer 1

我并不是真的理解所有的消极性，但让我快速解释他们所谈论的内容。您正在 inFile 中使用 hasNext（）方法，该方法返回一个布尔值，以确定是否具有“下一个”值。在这种情况下，它会检查是否有下一个双倍。问题是你要为这个布尔值分配一个双精度数组，你不能这样做。

以下是我使用您的代码工作的内容;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.*;
public class arrayLabFirst
{
    public static void main(String[] args) throws FileNotFoundException
    {
        double[ ] temperatures = new double[10];
        Scanner inFile = new Scanner(new File("data.txt")); 
        for (int index = 0; index < temperatures.length; index++)
            if(inFile.hasNext())
                temperatures[index] = inFile.nextDouble();
            else
                continue;

        printArray(temperatures);
        System.out.println("The average of the temperatures entered is: " + arrayAverage(temperatures));
        System.out.println("The greatest temperature is: " + greatest(temperatures));
        System.out.println("The lowest temperature is: " + lowest(temperatures));

        inFile.close();
    }
    public static void printArray(double[] temperatures)
    {
        System.out.print("Input Array:\n[");
        for (int i = 0; i < temperatures.length; i++)
        {
            System.out.print(temperatures[i]);
            if(i < temperatures.length - 1)
            {
                System.out.print(", ");
            }
        }
        System.out.println("]\n");
    }
    public static double arrayAverage(double[] temperatures)
    {
        double sum = 0;
        for (int i = 0; i < temperatures.length; i++)
            sum += temperatures[i];
        return sum/temperatures.length;
    }
    public static void countDays(double[] temperatures)
    {
        int aboveCount = 0;
        int belowCount = 0;
        for (int i = 0; i < temperatures.length; i++)
        {
            if (i > 32)
                aboveCount++;
            else
                belowCount++;
        }
        System.out.println("number of days above freezing: " + aboveCount);
        System.out.println("number of days below freezing: " + belowCount);
    }
    public static double greatest(double[] temperatures)
    {
        int maxIndex = 0;
        for (int index = 1; index < temperatures.length; index++)
            if (temperatures[maxIndex] < temperatures[index])
                maxIndex = index;

        return temperatures[maxIndex];
    }
    public static double lowest(double[] temperatures)
    {
        int minIndex = 0;
        for (int index = 1; index < temperatures.length; index++)
            if (temperatures[minIndex] > temperatures[index])
                minIndex = index;        

        return temperatures[minIndex];
    }
}

如何从txt文件执行代码

1 个答案: