Given a two-dimensional array, calculate the sum of all its elements。用Java编写

可以使用双重循环遍历二维数组，并将每个元素的值相加，最终得到总和。以下是Java代码示例：

public class TwoDimensionalArraySum {
    public static void main(String[] args) {
        int[][] arr = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
        int sum = 0;

        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr[i].length; j++) {
                sum += arr[i][j];
            }
        }

        System.out.println("The sum of all elements in the array is: " + sum);
    }
}

输出结果为：

The sum of all elements in the array is: 45