Pointer in C programming

Published on : 3rd Oct 2021
Pointer is an important concept in C programming. A programmer must have to know the concept of pointer. 
Why do we need pointer ?
We cannot return more than one value from a function. But, we can return an address. An array is nothing but a pointer. So, we can return an array that can store more than one value. We don't pass an entire array to a function rather we pass the base address of an array to a function using pointer.
Definition :
A pointer is a variable which is used to store the address or reference of another variable.
Pointer declaration :
int *p; 
Here, p is a pointer which can store the value of an int type variable.
Pointer declaration with initialization :
int a = 100;
int *p = &a;
Visualization of pointer :

Note : The address of a variable may vary because OS allocate memory for a variable at the time of execution.
Explanation :
Here, p is storing the address of a. So, p is pointing to a. Hence, p is a pointer.
Source Code :
#include <stdio.h>

int main(int argc, char** argv)
{
	int a = 100;
	int *p = &a;
	printf("Address of a = %u\n", &a);
	printf("Value of p = %u\n", p);
	printf("Value at address %u = %d\n", p, *p);
	return 0;
}
Output :
Address of a = 6487572
Value of p = 6487572
Value at address 6487572 = 100