Differences between array pointers and pointer Arrays

The difference between an array pointer and a pointer array is that the array pointer p is a pointer, And the pointer array p is an array that stores N pointer variables. I. array pointer int (* p) [n] key points: () High priority ([], () has the same priority, but their direction is from left to right, therefore, run * p in parentheses first. p is a pointer pointing to an integer one-dimensional array. The length of this one-dimensional array is n, or the step size of p. That is to say, when p + 1 is executed, p must span the length of n integer data (n * sizeof (int )). To assign a two-dimensional array to a pointer, the value should be: int a [3] [4]; int (* p) [4]; // This statement defines an array pointer pointing to a one-dimensional array containing four elements. P = a; // assign the first address of the Two-dimensional array to p, that is, a [0] Or & a [0] [0] p ++; // <=> a [1] <=> when p [1] is used to point to a two-dimensional array, its reference is the same as the array name reference, that is, a <=> p. For example, to represent an element a [I] [j] In column j of row I in the array: p [I] [j] <=> a [I] [j] <=> * (p [I] + j) <=> * (a [I] + j) <=> * (p + I) + j) <=> * (a + I) + j) <=> (* (p + I) [j] <=> (* (a + I) [j] 2. pointer array int * p [n] highlights: [] high priority. It is first combined with p to form an array, and then int * indicates that this is an integer pointer array, which has n Array elements of pointer type: that is, it is an array containing n pointers. This assignment is also incorrect: p = a; Because p is a right value, the value of p only exists in p [0], p [1], p [2]... p [n-1], and they are pointer variables that can be used to store variable addresses. But it can be like this * p = a; here * p represents the value of the first element of the pointer array and the value of the first address of. To assign a two-dimensional array to a pointer array: int * p [3]; int a [3] [4]; for (I = 0; I <3; I ++) p [I] = a [I]; here int * p [3] indicates that three pointer variables exist in the memory of a one-dimensional array, which are p [0], p [1], and p [2]. By default, all three pointer variables point to NULL, so assign values respectively.