C Pointer Essence

Let 's start with the simple type and analyze it slowly:

 

int p; This is an ordinary integer variable.

 

int *p; Start with P first, and then combine with * so that P is a

//Pointer, then combined with int, description pointer to

//content is of type int. So P is a return to the whole

pointer to//type data

 

int p[3]; Start with P, first with [] to show that P is a number

//Group, and then combine with int to show that the element in the array is an integer

//Type, so p is an array of integral types of data

 

int *p[3]; Start with P first, and [] first, because its priority

//ratio * High, so p is an array, and then combined with *, description

//The elements in the array are pointer types, and then combined with int,

//Description The type of content pointed to by the pointer is integral, so

//p is an array of pointers that return integer data

 

Int (*p) [3]; Start with P first, and then combine with * to show that P is a pointer

//And then combined with [] This step can be ignored, just for

//A change of priority), stating that the pointer points to something that is a

//array and then combined with int to show that the elements in the array are

//integral type. So P is a number that points to an integral type of data

//Group's pointers

 

int **p; Start with P first, combine with *, say P is a pointer, but

//later combined with *, indicating that the pointer points to the element is a pointer, however

//Then combined with int to show that the pointer points to an element that is an integer

//Type data. Because two pointers and more advanced pointers are rarely used

//In complex types, so the later more complex types we

//No multilevel pointers are considered, at most only one pointer is considered.

 

int P (int); Starting with P, we combine with () to show that P is a function and then enter

//() analysis, indicating that the function has a parameter of an integer variable

//Then combine with the outer int to indicate that the return value of the function is

//An integral type of data

Int (*p) (int); Starting at p, first with the pointer, the P is a pointer, and then the

///() The combination of the pointer to a function, then the//int with the (), stating that the function has an int type parameter, and then combining with the outermost//int, stating that the return type of the function is an integral type, so p is a reference// A pointer to a function that has an integer parameter and returns the type integer

 

int * (*p (int)) [3]; You can skip, not look at this type, too complex

//Starting from P, first with (), stating that P is a function and then entering

//Into (), in conjunction with int, indicates that the function has an integer variable

//parameters, then combined with the outside *, the function returned is

//A pointer, and then to the outermost layer, first and [] combined, indicating

//The returned pointer points to an array and then combines with *, saying

//The elements in the array are pointers, and then combined with int to indicate

//The PIN is pointing to an integer data. So p is a parameter for a

//Integer data and returns an array of integer pointer variables

//The function of the pointer variable.