C language Pointer 1

#include  <stdio.h>/*2018-05-26 address is the number of memory cells pointer is the address, The address is the pointer address is the memory unit number pointer variable is the address of the variable pointer (0019ff38) and pointer variable (p) is two different concepts but note: We usually describe the pointer variable as a pointer, the actual meaning is not the same */int main (void {Int * p;      // p is the name of the variable, int * represents the address of the int type variable that the p variable holds    // int *p  does not mean to define a variable named *p   // int *p  should understand this: p is the variable name, the data type of the p variable is int  * type   //The so-called int * type is actually the type that holds the INT variable address int i = 3;int j;p = &i;   //ok /*1,p Save the address of I, so P point to i2,p is not i,i nor p, more accurately, the value of the modified P does not affect the value of I, modify the value of I will not affect the value of P 3, if a pointer variable points to a common variable, then * The pointer variable is exactly the same as the normal variable example: if P is a pointer variable, and p is the address of the normal variable I, p points to the ordinary variable i*p  is exactly the same as I or say: In all occurrences of *p can replace I in all occurrences of I can be replaced by *pprintf ("%d\n", i),  //output 3printf ("%d\n", *p),  //output 3*p  is the variable */j = *p;printf with the content of P as the address ("i =  %d ,j = %d ,*p = %d \n ", i,j,*p);   //results i = 3  , j = 3 ,*p = 3printf ("I's address is:%p\n", &i); &nbsThe%p used in the p; //c language to output the value of the pointer type itself. This means that%p is used to output the address printf ("J's address is:%p\n", &j);p rintf ("P's address is:%p\n", &p);p rintf ("P's value is:%p\n", p);/* Output: i = The address of the  3 ,j = 3 ,*p = 3i is: 0019ff38j address is: 0019ff34p address is: 0019FF3CP value is: 0019FF38*/ return 0;} The address of the variable i is the value of 0019ff38,i is the 3//variable p is the address of the 0019ff3c,p value is 0019ff38, that is, the value of P is the address of I//*p  is the content of P as the address (that is, I address 0019ff38) variable, so * The value of P is 3//note that the address is definitely not the case when you run it, but the address of I and the value of P must be the same

C language Pointer 1