C Language Basics Tutorial (iv) Pointers, structures, unions, and enumerations (4)

2.1. Pointers to array elements
We define an integer array and a pointer variable that points to an integral type:
int a[10], *p;
As described earlier, you can point an integer pointer p to any element in the array, assuming that the assignment operation
p=&a[0];
At this point, p points to the No. 0 element in the array, a[0], and the pointer variable p contains the address of the array element a[0], because the array elements are stored continuously in memory, so we can indirectly access any element of the array through the pointer variable p and its related operations.
In Turbo C, the array name is the address of the No. 0 element of the array, so the following two statements are equivalent
p=&a[0];
P=a;
According to the address operation rule, a+1 is the address of a[1], A+i is the address of a[i].
Here we use pointers to the address of the array element and several representations of the content.
(1). P+i and A+i all represent the addresses of a[i], or they all point to the array number-I element, which points to a[i].
(2). * (P+i) and * (A+i) All represent the contents of the objects referred to P+i and a+i, that is, a[i].
(3). A pointer to an array element can also represent the form of a group, that is, it allows pointer variables to be subscript, such as p[i] and * (p+i) equivalent.
if: p=a+5;
Then p[2] is equivalent to * (p+2), because P points to a[5], so p[2] is equivalent to a[7. and p[-3] is equivalent to * (p-3), it means a[2].