Dark Horse programmer--"Dark Horse video Note"--pointer to C language Foundation

1. Definition of pointers

Format: Variable type * variable name;

   1:  //defines a pointer variable p

   2:      //pointer variable can only store address

   3:      //Pointer is a function: can access the corresponding storage space according to an address value

   4:      //pointer variable p before INT: pointer variable p can only point to data of type int

   5:  

   6:  int *p;

2. Pointers pointing to pointers

3. Pointers and Arrays

1) How array elements are accessed int ages[5];int *p;p = ages;1> array name [subscript] ages[i]2> pointer variable name [subscript] p[i]3> * (P + i) 2) pointer variable +1, address value exactly how much, depending on the type of pointer int * 4 char * 1 double * 8

4. Point of attention of the pointer

1

   1:  /* Not recommended notation, int *p can only point to data of type int

   2:      int *p;

   3:      Double d = 10.0;

   4:      p = &d;*/

2

   1:  /  * Pointer variable can only store address

   2:      int *p;

   3:      p = $;

   4:      * /

3

/* Pointer variable is not initialized, do not use indirect access to other storage spaces

    int *p;

    printf ("%d\n", *p);

    */

4

When defining a variable, the * is only a symbol, no other special meaning

    int *p = &a;

5

    Incorrect wording

    *p = &a;

    p = &a;

6

The function of this time: access to the storage space pointed to by the variable p

    *p = 20;

Dark Horse programmer--"Dark Horse video Note"--pointer to C language Foundation