Examples of Pointer Dereferencing
Example 1:
Using a pointer to access and modify the value of an integer variable.
C
// C Program to illustrate the dereferencing of pointer#include <stdio.h>int main(){ // Declare integer variable number int num = 10; // Declare pointer to store address of number int* ptr = # // Print the value of number printf("Value of num = %d \n", num); // Print Address of the number using & operator printf("Address of num = %d \n", &num); // Print Address stored in the pointer printf("Address stored in the ptr = %p \n\n", ptr); printf("Dereference content in ptr using *ptr\n\n"); // Access the content using * operator printf("Value of *ptr = %d \n", *ptr); printf("Now, *ptr is same as number\n\n"); printf("Modify the value using pointer to 6 \n\n"); // Modify the content in the address to 6 using pointer *ptr = 6; // Print the modified value using pointer printf("Value of *ptr = %d \n", *ptr); // Print the modified value using variable printf("Value of number = %d \n", num); return 0;} |
Output
Value of num = 10 Address of num = 0x7ffe47d51b4c Address stored in the ptr = 0x7ffe47d51b4c Dereference content in ptr using *ptr Value of *ptr = 10 Now, *ptr is same as number Modify the value using pointer to 6 Value of *ptr = 6 Value of number = 6
Example 2: Dereferencing Double Pointer
The double pointers can also be dereferenced using the same logic but you will have to use the indirection operator two times: One for moving to the pointer the double pointer is pointing to and the other for accessing the actual value.
C
// C program to dereference double pointer#include <stdio.h>int main(){ int var = 10; int* ptr = &var; // double pointer int** dptr = &ptr; // dereferencing the double pointer printf("Accesing value from double pointer using " "**dptr: %d", **dptr); return 0;} |
Output
Accesing value from double pointer using **dptr: 10
Just like that, we can dereference pointers of any level.
Dereference Pointer in C
We know that the pointer variable can store the memory address in C language and in this article, we will learn how to use that pointer to access the data stored in the memory location pointed by the pointer.
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