Question

我需要计算数组中整数的随机输入。一切工作正常，但我为每个Input获得了数组内所有值的新计算。

有人知道如何解决这个问题吗？

这是我的代码：

public static void main(String[] args) throws IOException {
    Scanner sc = new Scanner(System.in);
    ArrayList<Integer> numbers = new ArrayList<>();

    while (sc.hasNextInt()) { // this loop breaks there is no more int input.
        numbers.add(sc.nextInt());

        int l = numbers.size();

        double total = 0;

        for (int i = 0; i < numbers.size(); i++) {

            total = total + numbers.get(i);

            double average = total / numbers.size();
            System.out.println("The average is: " + average);
        }
        System.out.println(numbers);
    }
}

Answer 1

正如所指出的，您应该仅在找到所有数字的总和后来计算数字的平均值。

您的程序需要分成几个单独的步骤，这些步骤应该一个接一个地执行，而不是一次执行：

检索用户输入，将每个整数添加到列表中
遍历列表中的所有整数，并添加到total
计算平均值
显示结果

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    ArrayList<Integer> numbers = new ArrayList<>();

    while (sc.hasNextInt())
        numbers.add(sc.nextInt());
    sc.close(); // Remember to close the input stream when finished

    double total = 0;
    for (int num : numbers) // Loop through all ints in the list
        total += num; // Add each int to total

    double average = total / numbers.size();
    System.out.println("The average is: " + average);
    System.out.println(numbers);
}

Answer 2

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

        Scanner sc = new Scanner(System.in);
        ArrayList<Integer> numbers = new ArrayList<Integer>();
        while (sc.hasNextInt()) { // this loop breaks there is no more int input.
            numbers.add(sc.nextInt());

            int l = numbers.size();

            double total = 0;


        }

for (int i = 0; i < numbers.size(); i++) {

                total = total + numbers.get(i);

                double average = total / numbers.size();
                System.out.println("The average is: " + average);
            }

            System.out.println(numbers);

}

Answer 3

这应该可以解决您的问题。每个循环的Java文档： https://docs.oracle.com/javase/8/docs/technotes/guides/language/foreach.html

    public static void main(String[] args) throws IOException {
       
        double total;
        double average;
        
        Scanner sc = new Scanner(System.in);
        ArrayList<Integer> numbers = new ArrayList<Integer>();
        while (sc.hasNextInt()) { // this loop breaks there is no more int input.
            numbers.add(sc.nextInt());

            int l = numbers.size(); //this line is redundant as its never used 
            
            //this is a different and more efficient way to traverse through the list for this               //problem, check comment for the documentation
            for (int currentNumberInList : numbers) {
                total = total + currentNumberInList;
            }
            System.out.println(numbers); //this only prints the numbers you 
                                         //stored in the list
            average = total / numbers.size();
            System.out.println("The average is: " + average);

        }
    }

计算数组中整数输入的平均值

3 个答案: