取数组中元素的平均值

Question

所以我准备明天进行测验，我正在玩数组，我问用户想要输入多少个测试，然后询问每个测试的分数。我遇到的问题是总结测试，它没有总结所有，请帮助我

import java.util.Scanner;

public class Arrays {
    public static void main(String args []){
        int numOfElements;

        Scanner input = new Scanner(System.in) ;

        System.out.println("How many tests are you going to input? ");
        numOfElements = input.nextInt();

        double array[] = new double [numOfElements];

        for (int i=0; i<array.length; i++){
            System.out.println("Enter the test # " + (i+1) + ": ");
            array[i] = input.nextDouble();
        }


        for (int i = 0; i<array.length; i++ )
        {

            System.out.print("Test #"+(i+1)+"= "+array[i] + " pts\n");

        }


        for (int m= 0; m<array.length; m++)
        {   //average value

            double sum = 0;

            sum = sum + array[m]; //get the sum\

            double average = sum / array.length; //get the average value


            //print out the sum of elements in an array

            System.out.print("Your total points are: "+sum);

            //print out the average grade

            System.out.println("Your grades is "+average +"%");
        }


    }

Answer 1

您的问题在这里：

double sum = 0

在每次循环迭代期间重置您的计数器！

因此，对于初学者来说，您必须将该语句移到 for 循环的前面！ 'average'!

相同

Answer 2

你应该在循环中总结分数。之后，你打印结果。

double sum = 0;
for (int m= 0; m<array.length; m++)
{   //average value

    sum = sum + array[m]; //get the sum\


}

double average = sum / array.length; //get the average value


//print out the sum of elements in an array

System.out.print("Your total points are: "+sum);

//print out the average grade

System.out.println("Your grades is "+average +"%");

Answer 3

double sum 和 double average 每次迭代都会重置，将它们声明为 for 循环外的局部变量，并在迭代完成后打印 average 和 sum

    double sum = 0;
    for (int m = 0; m < array.length; m++) {
        sum = sum + array[m];
    }
    System.out.print("Your total points are: " + sum);
    System.out.println("Your grades is " + sum / array.length + "%");

在java8+

    double array[] = new double[numOfElements];
    DoubleSummaryStatistics dss = Arrays.stream(array).summaryStatistics();
    System.out.println("average " + dss.getAverage());
    System.out.println("sum " + dss.getSum());

取数组中元素的平均值

Take the average of elements in array

java

arrays

average

sum

elements