在此程序中,我必须用用户输入的值填充2D数组,并找到所有数组元素的平均值。但是,该程序通过将总和除以行数而不是数字数来找到平均值。我尝试将average本身设置为2D数组,但它只能识别一个参考,而不是两个参考。暂停
public static void main(String[] args) {
int[][] array = createArray();
System.out.printf("The average of this array is " + "%.2f", average(array));
}
public static int[][] createArray() {
Scanner sc = new Scanner(System.in);
System.out.print("Enter the number of rows: ");
int numRows = sc.nextInt();
System.out.print("Enter the number of columns: ");
int numColumns = sc.nextInt();
int[][] array = new int[numRows][numColumns];
System.out.println("Enter " + array.length + " rows and " + array[0].length + " columns");
for (int row = 0; row < array.length; row++)
for (int column = 0; column < array[0].length; column++)
array[row][column] = sc.nextInt();
return array;
}
public static double average(int[][] a) {
int sum = 0;
double average = 0;
for (int row = 0; row < a.length; row++) {
for (int column = 0; column < a[row].length; column++) {
sum += a[row][column];
}
average = sum / a.length;
}
return average;
}
}
问题在这里:
for (int row = 0; row < a.length; row++) { for (int column = 0; column < a[row].length; column++) { sum += a[row][column]; } average = sum / a.length; }
问题是您在循环中的每次迭代中都重新分配 average
。相反,您应该在所有循环完成之后计算它:
for (int row = 0; row < a.length; row++) {
for (int column = 0; column < a[row].length; column++) {
sum += a[row][column];
}
}
average = (double) sum / (a.length * a[0].length);
乘积(a.length * a[0].length)
将为您提供数组中所有数组的大小。您可以在平均值计算中将强制类型转换添加到(double)
,以避免整数算术问题(例如25/6
为4
)。
请注意,如果数组足够大,sum
可能会溢出。