将数组元素与方法的返回值进行比较

Question

我有一种方法可以根据用户输入的月份数组计算最小和最大降雨量。我的问题是我的方法返回最小值和最大值的数量，我需要它返回降雨量最高或最低的月份。我不确定如何将我的 min 和 max 方法与月份数组进行比较。我想如果我可以说在索引 5 处找到了最小值，那么也有办法提取月份数组的索引 5。

我尝试了多种类型的 for 循环和嵌套 for 循环，但似乎无法获得正确的月份。

public static void main(String[] args) {

    String[] months = {"January", "February", "March","April","May","June","July","August","September","October","November","December"};
    double[] rainfall = new double[months.length];

    Rainfall amazon = new Rainfall();

    //scanner to get user input
    Scanner scanner = new Scanner(System.in);

    //for loop to iterate through the months to get user input of rainfall each month
    for(int i = 0; i<rainfall.length; i++) {
        System.out.println("How much rainfall did you recieve, in inches, for the month of: " + months[i]);
        rainfall[i] = scanner.nextDouble();

        //while statement to reject negative numbers         
        while(rainfall[i] < 0) {
            System.out.println("You can not enter a negative number");
            System.out.println("How much rainfall did you recieve for the month of: " + months[i]);
            rainfall[i] = scanner.nextDouble();  
        }
    }

    System.out.println("total rainfall: " + amazon.getTotalRainfall(rainfall) + 
                       " average Rainfall: " + amazon.getAverageRainfall(rainfall) + 
                       " min: " + amazon.getMinRainfall(rainfall) + 
                       " max: " + amazon.getMaxRainfall(rainfall));

}

public double getMaxRainfall(double[] rainfall) {
    double max = rainfall[0];
    for(int i = 1; i < rainfall.length; i++)
        if(rainfall[i] > max) {
            max = rainfall[i];
        }
    return max;
}      

public double getMinRainfall(double[] rainfall) {
    double min = rainfall[0];
    for(int i = 1; i < rainfall.length; i++)
        if(rainfall[i] < min) {
            min = rainfall[i];
        }
    return min;
}

我需要知道降雨量最高和最低的月份

Answer 1

解决此问题的方法是跟踪最高降雨量的指数而不是数值。您现在遇到的问题是您有 2 个不同的数组，并且其中一个的值与另一个不相关。

为此，您可以执行以下操作：

    public int getMaxRainfallIndex(double[] rainfall) {
        int max = 0;
        for (int i = 1; i < rainfall.length; i++)
            if (rainfall[i] > rainfall[max]) {
                max = i;
            }
        return max;
    } 

然后您可以使用此返回值从原始 2 个数组中获取实际降雨量和月份。

然而，一种更简洁的方法是创建一个单独的类来存储两条信息，这样您就可以将包含两条信息的整个对象一起返回。这样您甚至不必担心保留 2 个单独的数组。

应该是这样的：

    public static void main(String[] args) {
        Rainfall[] rainfall = new Rainfall[12];
        //Do everything else
    }

    public class Rainfall {
        private String month;
        private double rainfall;

        //Constructor, Getters + Setters
    }

Answer 2

一种可能的解决方案是返回月份的索引，例如，您的 getMaxRainfall 方法应如下所示：

 public int getMaxRainfallIndex(double[] rainfall)
      {
        int maxIndex = 0;
        double max = rainfall[0];
              for(int i = 1; i < rainfall.length; i++)
                 if(rainfall[i] > max)
                    {
                     max = rainfall[i];
                     maxIndex = i;
                    }
              return maxIndex;
     }   

在您的main 中，您应该使用该索引来获取月份和降雨量：

int index = amazon.getMaxRainfallIndex(rainfall);
system.out.println("month of max rainfall: " + months[index]);
system.out.println("max rainfall: " + rainfall[index]);

Answer 3

您可以创建一个单独的class，而不是单独管理两个数组：

public class RainfallByMonth {
    private double rainfall;
    private String month;

    // Getter/Setters here
}

在你的主要方法中：

public static void main(String[] args) {
    RainfallByMonth[] rainfallByMonths = new RainfallByMonth[12];
    String[] months = new DateFormatSymbols().getMonths(); // array of months

    Scanner scanner = new Scanner(System.in);
    for (int i = 0; i < rainfallByMonths.length; i++) {
        System.out.println("How much rainfall did you receive, in inches, for the month of: " + months[i]);
        rainfallByMonths[i].setMonth(months[i]);
        rainfallByMonths[i].setRainfall(scanner.nextDouble());
    }
    RainfallByMonth maxRainfall = getMaxRainfall(rainfallByMonths);
    // Now you can print the results here
}

按月计算最大降雨量：

public static RainfallByMonth getMaxRainfall(RainfallByMonth[] rainfallByMonths) {
    RainfallByMonth maxRainfall = rainfallByMonths[0];
    for(int i = 1; i < rainfallByMonths.length; i++) {
        if(rainfallByMonths[i].getRainfall() > maxRainfall.getRainfall()) {
            maxRainfall = rainfallByMonths[i];
        }
    }
    return maxRainfall;
}

同样，min 的情况反之亦然（只是条件会有所不同）。这将更容易管理。

Answer 4

public static void main(String[] args) {
      String[] months = {"January", "February", "March","April","May","June","July","August","September","October","November","December"};
      int[] weather = {10, -1, 7,44,33,6,22,54,89,21,8,51};
      int max = 0;
      int index= 0;
      for (int i=0;i<weather.length-1;i++  ){
          if (weather[i] > m){
              max = weather[i];
              index= i;
          } 
      }
      System.out.println(months[index]); 
}

查找最高月份的示例程序。 要找到最低月份的降雨量，请在 if 条件下使用小于符号