数组指针寻址

一维数组寻址

数组名表示[数组第0个元素]的[地址][常量]

type array[M]

array[N] address is

(int)array + sizeof(type) * N

 

数组长度

sizeof(array) / sizeof(array[0])

 

二维数组寻址

type array[N][M]

type array[x][y] address is:

(int)array + sizeof(type[M]) * x + sizeof(type) * y

 

指针寻址

array是表示数组第0个元素地址的指针常量，指针类型为元素类型

type array[M];

array[n] <==> *(type *)((int)array +sizeof(type)*n);

 

type *ptr = xxxx;

type *ptrTest = xxxx;

int n = xxxx;

 

(ptr + n) is (int)ptr + sizeof(type)*n;

ptr + n <==> (type * const)((int)ptr +sizeof(type)*n);

 

ptr - ptrTest <==> ((int)ptr - (int)ptrTest) /sizeof(type);

 

array[n] == *(array + n);

&array[n] == array + n;

 

type *ptr = array;

type[n] == array[n];

ptr++; //OK

array++; //ERROR, array is pointer const