函数和二位数组

int data[3][4] = {{1,2,3,4}, {9,8,7,6}, {2,4,6,8}};
int total = sum(data, 3);
函数原型:
方式一 : int sum(int (*ar2)[4], int size);
方式二 : int sum(int ar2[][4], int size);

数组名代表了整个数组的大小 int arr[3][10]; sizeof(arr[0]) == 40

int arr[16] = {0};
arr[i] == *(arr+i)
&arr[i] == arr+i