Question

“计算正数和负数并计算数字的平均值”编写一个读取未指定数量的整数的程序，确定已读取的正负值的数量，并计算输入值的总和和平均值（不是计数零。。程序以输入0结束。将平均值显示为浮点数。“

我不知道我做错了什么

import java.util.Scanner;

public class NewClass {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        int positive = 0, negative = 0, total = 0, count = 0;

        double average;

        System.out.println("Enter the number: ");
        int number;

        while ((number = input.nextInt()) != 0) {
            total += number;
            count++;
            if (number > 0) {
                positive++;
            } else if (number < 0) {
                negative++;
            }
        }
        average = total / count;
        System.out.println("The number of positives is " + positive);
        System.out.println("The number of negatives is " + negative);
        System.out.println("The total is " + total);
        System.out.printf("The average is %d ", average);
    }
}

Answer 1

首先：它应该是average = (double)total / count;，因为int / int比得到一个整数。

第二：System.out.println("The average is " + average);或System.out.printf("The average is %f ", average);

Answer 2

如果你想要数字的平均值，你不能将整数total除以整数count，因为结果将是一个整数，它不考虑小数点。

import java.util.Scanner;

public class NewClass {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        int positive = 0, negative = 0, total = 0, count = 0;

        double average;

        System.out.println("Enter the number: ");
        int number;

        while ((number = input.nextInt()) != 0) {
            total += number;
            count++;
            if (number > 0) {
                positive++;
            } else if (number < 0) {
                negative++;
            }
        }
        average = (double) total / count;
        System.out.println("The number of positives is " + positive);
        System.out.println("The number of negatives is " + negative);
        System.out.println("The total is " + total);
        System.out.printf("The average is: " + average);
    }
}

此外，您不必在行System.out.printf("The average is %d", average);

中使用％d

您可以编写System.out.printf("The average is: " + average);，因为当您打印出一个字符串时，括号内连接的任何内容也将转换为字符串，并打印出来

Answer 3

只需将int变量乘以1.0即可将其转换为浮点变量 average=1.0*total/count; 这应该做。您可以使用以下语句来显示值 System.out.println("The average of numbers is "+average);

Answer 4

// Scanner is in java.util package
import java.util.Scanner;
class CountPandN
{
    public static void main(String args[])
    {
        // create a Scanner object
        Scanner input = new Scanner(System.in);
        // prompt user to enter numbers
        System.out.println("Enter + and - numbers");
        System.out.println("Enter 0 when you're finished");
        // initialize the variables
        int n, countP, countN, count;
        n = input.nextInt();
        countP = 0;
        countN = 0;
        count = 0;
        int sum = n;
        float average = (float) sum / 2;

        while (n != 0)
        {
            n = input.nextInt();
        count++;

        if(n >= 0)
            countP++;
        if (n < 0)
            countN++;
        }
        System.out.println("Total positive " + countP);
        System.out.println("Total negative " + countN);
        System.out.println("Total numbers " + count);
        System.out.println("Total average " + average);
    }
}

Answer 5

如果您仅用System.out.printf("The average is %d ", average);来更改System.out.printf("The average is " +average);，即如果您删除%d并使用'+'而不是','，那么它将为您工作，并且得到浮动的答案，您需要使用类型转换。即在(double)

中添加average = (double)total / count;

编写一个读取未指定数量的整数的程序

5 个答案: