示例

//Visual Studio中加上这句才可以使用scanf()
//否则只能使用scanf_s()
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdbool.h>

#define ROWS 3
#define COLS 4
void sum_rows(int ar[][COLS], int rows);
void sum_cols(int [][COLS], int);//省略形参名
int sum2d(int (*ar)[COLS], int rows);//指针表示法

//多维数组只能省略最左边括号的大小，如ar[][2][3]
//ar[2][3] 第1个括号里的2会被编译器忽略

//编译器会将数组表示法转成指针表示法(因为处理指针效率更高)

//argc: 参数个数 argv[]: 参数数组
int main(int argc, char *argv[])
{
	int junk[ROWS][COLS] = {
		{2, 4, 6, 8},
		{3, 5, 7, 9},
		{12,10,8, 6}
	};

	sum_rows(junk, ROWS);
	sum_cols(junk, ROWS);
	printf("Sum of all elements = %d\n", sum2d(junk, ROWS));

	system("pause");
	return 0;
}

void sum_rows(int ar[][COLS], int rows)
{
	int r;
	int c;
	int tot;
	for (r = 0; r < rows; r++)
	{
		tot = 0;
		for (c = 0; c < COLS; c++)
			tot += ar[r][c];
		printf("row %d: sum = %d\n", r, tot);
	}
}

void sum_cols(int ar[][COLS], int rows)
{
	int r;
	int c;
	int tot;
	for (c = 0; c < COLS; c++)
	{
		tot = 0;
		for (r = 0; r < rows; r++)
			tot += ar[r][c];
		printf("col %d: sum = %d\n", c, tot);
	}
}

int sum2d(int ar[][COLS], int rows)
{
	int r;
	int c;
	int tot = 0;
	for (r = 0; r < rows; r++)
		for (c = 0; c < COLS; c++)
			tot += ar[r][c];
	return tot;
}

运行测试