C Language Pointers

Lesson three Homework

A pointer is a variable that stores the memory address of a computer. Reading data from the memory pointed to by the pointer is called the value of the pointer. Pointers can point to variable addresses of specific types, such as int,long , and double. The pointer can also be a void type,aNULL Pointer, and an uninitialized pointer.

1)

#include <stdio.h>

int main ()

{

int *ptr; declares an int pointer

int val = 1; declares an int value

PTR = &val; Assigning a reference to an int value for a pointer

int deref = *ptr; value the pointer to print the contents stored in the pointer address

printf ("Deref address =%ld, value =%d\n", PTR, deref);

}

2. Pointers and Arrays

#include <stdio.h>

int main ()

{

int myarray[4] = {1,2,3,0};

int *ptr = myarray;

printf ("PTR address =%ld, value *ptr=%d\n", ptr,*ptr);

ptr++;

printf ("PTR address =%ld, value *ptr=%d\n", ptr,*ptr);

ptr++;

printf ("PTR address =%ld, value *ptr=%d\n", ptr,*ptr);

ptr++;

printf ("PTR address =%ld, value *ptr=%d\n", ptr,*ptr);

}

3)

#include <stdio.h>

struct Person {

int age;

Char *name;

};

int main ()

{

struct person first;

struct person *ptr;

First.age = 21;

Char *fullname = "full name";

First.name = fullname;

PTR = &first;

printf ("age=%d, name=%s\n", First.age, Ptr->name);

}

C Language Pointers