如何平均输出小数？

Question

我在平均显示小数时遇到问题.它一直显示.00或.1.我试图把它放在一起,但我仍然得到相同的结果.另外,我想包括我输入的第一个整数,但我不知道如何.请帮助:

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

public class WhileSentinelSum 
{
static final int SENTINEL= -999;

public static void main(String[] args)
{
    // Keyboard Initialization
        Scanner kbin = new Scanner(System.in);

    //Variable Initialization and Declaration
        int number, counter;
        int sum =0;
        int average;

    //Input
        System.out.print("Enter an integer number: " );
        number = kbin.nextInt();
        counter=0;


    //Processing
    //Output
        while(number != SENTINEL)
        {
            counter++;
            System.out.print("Enter an  integer number: ");
            number = kbin.nextInt();
            sum += number;
        }

        if (counter !=0)
            System.out.println("\nCounter is: " + counter);
        else
            System.out.println("no input");

        average= sum/counter;
        System.out.println("The sum is " + sum);
        System.out.println("The average is " + average);


        System.out.println();

    }//end main
}//end class

Answer 1

即使你宣称average是double,在sum和counter变量int,所以Java仍然使用整数除法将其分配给前average,如5 / 10在结果0代替0.5.

double在分割之前将其中一个变量强制转换为强制浮点运算:

double average;

...
average = (double) sum / counter;

您可以在进入while循环之前处理计算中的第一个数字(如果它不是sentinel值).