C Language Basics Tutorial (iv) Pointers, structures, unions, and enumerations (6)

2.2.2 points to an array pointer consisting of n elements
In Turbo C, you can define the following pointer variables:
int (*p) [3];
The pointer P refers to an integer array pointer consisting of 3 elements. In the definition, parentheses are not small, otherwise it is an array of pointers, which is described later. The pointer to this array differs from the integer pointer described earlier, and when an integer pointer points to an integral array of elements, with the pointer (address) plus 1, which indicates the next element to the array, the address value increases by 2 (because the magnification factor is 2), and as defined above, points to a 3-element array pointer. The address value is increased when the address is added to the 1 operation
6 (the magnification factor is 2x3=6), this array pointer is used less in turbo C, but it is convenient when dealing with two-dimensional arrays. For example:
int a[3][4], (*P) [4];
P=a;
At the start, p points to the No. 0 row of the two-dimensional array, and when the p+1 operation is performed, the magnification factor is 4x2=8 at this point, so it exactly points to the 1th row of the two-dimensional array. As with the rules for computing two-dimensional array element addresses, *p+1 points to a[0][1],* (P+i) +j points to the array element A[i][j].
Example 1
int a[3] [4]={
{1,3,5,7},
{9,11,13,15},
{17,19,21,23}
};
Main ()
{
int I, (*b) [4];
b=a+1; /* b points to line 1th of a two-dimensional array, at which point *b[0] or
**b is a[1][0] * *
for (i=1;i<=4;b=b[0]+2,i++)/* To modify the point of B, 2 per increment * *
printf ("%d\t", *b[0]);
printf ("\ n");
For (i=0 i<2; i++) {
B=a+i; /* Modify the point of B to skip the two-dimensional array each time
One line * *
printf ("%d\t", * (b[i]+1));
}
printf ("\ n");
}
The results of the program operation are as follows:
9 13 17 21
3 11 19