Pointer array pointer difference

An array pointer is a pointer to the address of the first element of an array. In essence, it is a pointer;

A pointer array is an array whose elements are pointers (for example, int * P [3], which defines three pointers: P [0], p [1], and P [2 ), its essence is array.

 

Array pointer (also called row pointer)
Define int (* P) [N];
() A high priority indicates that 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.

 

To assign a two-dimensional array to a pointer, assign a value as follows:
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 ++; // after the statement is executed, that is, P = p + 1; p spans Row A [0] [] pointing to row A [1] []

Therefore, an array pointer is also called a pointer to a one-dimensional array or a row pointer.

 

 

Pointer Array

 

It can be understood as a two-dimensional array, but it is different.

Define int * P [N];
[] 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. The execution of p + 1 here is incorrect, so the value assignment is also incorrect: P = A; Because p is an unknown representation, only 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.

 

 

The most frequent use of pointer arrays is to store character arrays of different lengths.

 

char *week[]={"Monday","tuesday"，“wednesday”,“thursday”，“Friday”};

Differences between pointer arrays and Arrays

 

The most frequent use of pointer arrays is to store character arrays of different lengths.