二维数组在逻辑上是方阵，由行和列组成。
但是二维数组在物理上是线性的，按行来依次进行存放，内存是连续的。
二维数组名的步长是一行的长度，比如一下例子中：
age + 1 address is 00EFFC04
age + 2 address is 00EFFC14
因为每一行有四个元素，每个int类型的元素占四个字节，一行有16个字节，所以数组名age加1后地址增加了16个字节说明数组名的步长位一行的长度。
具体到每一个元素加1的时候，地址增加的是一个元素所占字节的大小，因此元素的步长即为元素本身的大小，例如：
age[2][0] + 0 address is 00EFFC14
age[2][0] + 1 address is 00EFFC18
示例及运行结果：
#include
int main()
{
int age[6][4];
for (int i = 0; i < sizeof(age)/sizeof(age[0]) ; i++)
{
printf("age + %d address is %p\n",i, age + i);
}
for (int i = 0; i < sizeof(age) / sizeof(age[0]); i++)
{
for (int j = 0; j < sizeof(age[0]) / sizeof(int); j++)
{
printf("age[%d][0] + %d address is %p\n",i,j,&age[i][0]+j);
}
}
}
输出结果：
age + 0 address is 0x7fffd98b9400
age + 1 address is 0x7fffd98b9410
age + 2 address is 0x7fffd98b9420
age + 3 address is 0x7fffd98b9430
age + 4 address is 0x7fffd98b9440
age + 5 address is 0x7fffd98b9450
age[0][0] + 0 address is 0x7fffd98b9400
age[0][0] + 1 address is 0x7fffd98b9404
age[0][0] + 2 address is 0x7fffd98b9408
age[0][0] + 3 address is 0x7fffd98b940c
age[1][0] + 0 address is 0x7fffd98b9410
age[1][0] + 1 address is 0x7fffd98b9414
age[1][0] + 2 address is 0x7fffd98b9418
age[1][0] + 3 address is 0x7fffd98b941c
age[2][0] + 0 address is 0x7fffd98b9420
age[2][0] + 1 address is 0x7fffd98b9424
age[2][0] + 2 address is 0x7fffd98b9428
age[2][0] + 3 address is 0x7fffd98b942c
age[3][0] + 0 address is 0x7fffd98b9430
age[3][0] + 1 address is 0x7fffd98b9434
age[3][0] + 2 address is 0x7fffd98b9438
age[3][0] + 3 address is 0x7fffd98b943c
age[4][0] + 0 address is 0x7fffd98b9440
age[4][0] + 1 address is 0x7fffd98b9444
age[4][0] + 2 address is 0x7fffd98b9448
age[4][0] + 3 address is 0x7fffd98b944c
age[5][0] + 0 address is 0x7fffd98b9450
age[5][0] + 1 address is 0x7fffd98b9454
age[5][0] + 2 address is 0x7fffd98b9458
age[5][0] + 3 address is 0x7fffd98b945c
可以看到每一个元素占了四个字节的大小，并且这24的元素的地址是连续的。
SageCat SageCat
107***2242@qq.com
7年前 (2018-03-27)