Java 如何计算二维阵列中的平均值？

首先，我对Java并不完全陌生，我已经上了一门Java课程。最近，我在一年后再次拿起它，对于如何计算二维整数数组中的平均值，我有点困惑。例如，下面是不包括平均计算的代码摘录：

  //Program fills array with x students and their corresponding test grades for n amount of tests

  System.out.println("Amount of students?");
  int numstudents = sc.nextInt();
  System.out.println("Amount of tests?");
  int numtests = sc.nextInt();
  
  int[][] marks  = new int [numstudents][numtests];
  int[] average  = new int [numstudents];
  
  for (int i = 0; i < numstudents; i++) {
     for (int j = 0; j < numtests; j++) {
        System.out.println("Enter the mark for student " + (i+1) + " on test " + (j+1));
        marks[i][j] = sc.nextInt();
        //Array is filled with grades. 
     }
  }

---

我认为应该计算平均值

    for (int i = 0; i < numstudents; i++) {
        //here
        for (int j = 0; j < numtests; j++) {
        }

for（int i=0；i

编写如下代码怎么样

    int eachsum = 0;
    for (int i = 0; i < numstudents; i++) {
        for (int j = 0; j < numtests; j++) {
             eachsum += marks[i][j];
        }
        average[i] = eachsum/numtests;
        System.out.println("The average for student " + (i+1) + " is " + average[i]);
        eachsum = 0;
    }

int-eachsum=0；
对于（int i=0；i

您可以执行以下操作：

int[] average = Arrays.stream(marks)
        .map(ints -> Arrays.stream(ints).summaryStatistics().getAverage())
        .mapToLong(Math::round)
        .mapToInt(Math::toIntExact)
        .toArray();

---

输入：

    int[][] marks = {
            {80, 70 ,90},
            {90, 65 ,90},
            {50, 70 ,70},
            {80, 75 ,85}
    };

输出：

[80,
 82,
 63,
 80]

[80,
 82,
 63,
 80]