JAVA二維數組代碼

Question

我想編寫一個程序，創建一個用測試數據初始化的二維int數組。 該程序無法運行。 我對代碼感到困惑，請幫助解決問題。如何更正我的代碼？ 謝謝。

    public class Int2DArray {

        private static int x;
        private static int y;





        public static int getTotal(int[][] numbers) {
            int total = 0;
            for (int x = 0; x < numbers.length; x++);
            for (int y = 0; y < numbers[x].length; y++);
            total = total + numbers[x][y];
            return total;
        }

        public static double getAverage(int[][] numbers) {
            double average = 0;
            average = getTotal(numbers) / (x + y);
            return average;
        }

        public static int getRowTotal(int[][] numbers, int index) {
            int total = 0;
            for (int y = 0; y < 3; y++) {
                total = total + numbers[index][y];
            }
            return total;
        }

        public static int getColumnTotal(int[][] numbers, int index) {
            int total = 0;
            for (int x = 0; x < numbers.length; x++) {
                total = total + numbers[x][index];
            }
            return total;
        }

        public static int getHighestInRow(int[][] numbers, int x) {
            int high = numbers[x][0];
            for (int i = 1; i < 3; i++) {
                if (numbers[x][i] > high) {
                    high = numbers[x][i];
                }
            }
            return high;
        }

        public static int getLowestInRow(int[][] numbers, int x) {
            int low = numbers[x][0];
            for (int i = 1; i < 3; i++) {
                if (numbers[x][i] < low) {
                    low = numbers[x][i];
                }
            }
            return low;
        }


    }
  public class Int2DArrayTest {

    public static void main(String[] args) {
        int[][] iarray = {{2, 1, 9}, {7, 3, 4}, {5, 6, 8}};
        System.out.println("Total:" + getTotal(iarray));
        System.out.println("Average:" + getAverage(iarray));
        System.out.println("Total of row 0" + getRowTotal(iarray, 0));
        System.out.println("Total of row 1" + getRowTotal(iarray, 1));
        System.out.println("Total of row 2" + getRowTotal(iarray, 2));
        System.out.println("Total of col 0" + getColumnTotal(iarray, 0));
        System.out.println("Total of col 1" + getColumnTotal(iarray, 1));
        System.out.println("Total of col 2" + getColumnTotal(iarray, 2));
        System.out.println("Highest in row 0" + getHighestInRow(iarray, 0));
        System.out.println("Highest in row 1" + getHighestInRow(iarray, 1));
        System.out.println("Highest in row 2" + getHighestInRow(iarray, 2));
        System.out.println("Lowest in row 0" + getLowestInRow(iarray, 0));
        System.out.println("Lowest in row 1" + getLowestInRow(iarray, 1));
        System.out.println("Lowest in row 2" + getLowestInRow(iarray, 2));
    }
}

Answer 1

您已將Int2DArray內部的方法Int2DArray為靜態

public static int getTotal(int[][] numbers) { //

因此，您需要將它們稱為靜態，以便像下面這樣使用它們：

System.out.println("Total:" + Int2DArray.getTotal(iarray));

Answer 2

我看到一個大錯誤：

您可以這樣解決：

public static int getTotal(int[][] numbers) {
            int total = 0;
            for (int x = 0; x < numbers.length; x++);
            for (int y = 0; y < numbers[x].length; y++);
            total = total + numbers[x][y];
            return total;
        }

代替

      public static int getTotal(int[][] numbers) { 
            int total = 0;
            for (int x = 0; x < numbers.length; x++){
               for (int y = 0; y < numbers[x].length; y++){
                  total = total + numbers[x][y];
              }
            }
            return total;
        }

或者更好（使用foreach）：

public static int getTotal(int[][] numbers) {
        int total = 0;
        for (int [] x : numbers){
            for (int y : x){
                total = total + y;
            }
        }
        return total;
    }

並在您的IDE中使用格式化熱鍵。

---

public static int getRowTotal(int[][] numbers, int index) {
            int total = 0;
            for (int y = 0; y < 3; y++) {
                total = total + numbers[index][y];
            }
            return total;
        }

在這里您使用常量3-這是不好的樣式，您需要將其提取為常量

---

public static double getAverage(int[][] numbers) {
            double average = 0;
            average = getTotal(numbers) / (x + y);
            return average;
        }

1. x和y未在您的代碼中初始化
2. 你為什么要除以x+y 。 您需要對元素數量進行划分。

Answer 3

您有兩次以下行，因此是一個明顯的語法錯誤。

 public class Int2DArrayTest {

此外，getAverage函數中也存在邏輯錯誤。

average = getTotal(numbers) / (x + y);

它顯示了被零除的異常。