java - 平均二维数组列

Question

我正在尝试对二维数组列进行平均。我的代码似乎将行中的数字相加，然后除以总数。在这个例子中应该只有 4 次赋值，但它循环了 12 次。有人知道我的代码有什么问题吗？这些数字是从文本文件输入的，位于完整代码的较高位置(不确定这是否会影响它)。

数组示例:

[2,3,6,7]
[4,5,6,7]
[2,2,2,2]

System.out.println("Average score of each assignment:");
//TODO: compute and print the average on each assignment
double total = 0;
int totallength = 0;
int assignment = 1;
for (int i = 0; i < myArray.length; i++) {
    for (int j = 0; j < myArray[i].length; j++) {
        total += myArray[i][j];
        totallength++;
        System.out.println("Assignment #" + assignment++
                + " Average: " + (total / totallength));
    }
}

这是我的输出:

Average score of each assignment:
Assignment #1 Average: 2.0
Assignment #2 Average: 2.5
Assignment #3 Average: 3.6666666666666665
Assignment #4 Average: 4.5
Assignment #5 Average: 4.4
Assignment #6 Average: 4.5
Assignment #7 Average: 4.714285714285714
Assignment #8 Average: 5.0
Assignment #9 Average: 4.666666666666667
Assignment #10 Average: 4.4
Assignment #11 Average: 4.181818181818182
Assignment #12 Average: 4.0

期望的输出:

Assignment #1 Average: 2.666666666
Assignment #2 Average: 3.333333333
Assignment #3 Average: 4.666666666
Assignment #4 Average: 5.333333333

Answer 1

您可以按如下方式进行:

public class Main {
    public static void main(String[] args){
        int [][]myArray= {
                {2,3,6,7},
                {4,5,6,7},
                {2,2,2,2},
        };      
        double total=0;
        int assignment=1;

        System.out.println("Average score of each assignment:");
        for(int i=0;i<myArray[0].length;i++) {
            for(int j=0;j<myArray.length;j++) {
                total+=myArray[j][i];          
            }
            System.out.println("Assignment #" + assignment++ + " Average: " + (total/3));
            total=0;
        }
    }
}

输出:

Average score of each assignment:
Assignment #1 Average: 2.6666666666666665
Assignment #2 Average: 3.3333333333333335
Assignment #3 Average: 4.666666666666667
Assignment #4 Average: 5.333333333333333