Pointers are variables that store memory addresses and allow indirect referencing of values in memory. They can be declared and initialized, with operators like & to get the address of a variable and * to dereference a pointer and access the value at a memory address. Pointers are useful for passing arguments by reference to functions to allow the function to modify the original variables, and for accessing elements in arrays by their offsets from the base address. Pointer arithmetic allows treating pointers like integers to advance through contiguous blocks of memory.

2. What are pointers?
 . Pointers are variables that contain memory addresses
as their values . A variable name directly reference a
value . A pointer indirectly references a value .
Referencing a value through a pointer is called
indirection . A pointer variable must be declared
before it can be used .

3. Pointer operators:
& _ _“address
operator” which
produces the memory
address of a data
variable .
*_ _ “dereferencing
operator” which
provides the contents in
the memory location
specified by a pointer .

4. Initialization of pointer:
Below example will clearly explain the initialization of pointer variable:
#include<stdio.h>
void main(){
int i ;
int *j;
i =10;
j=&i;
printf(“i=%d”,i);
printf(“*j=%d”,*j);
}

5. Pointers and arrays:
Since arrays a contiguous set of variables in
memory . We can access them with pointers.
#include <stdio.h>
int main( ) {
int a[ ] = { 1,2,3,4,5} ;
int *ptr ,i ;
ptr = a
for ( int i = 0 ; i < 5 ; i++ )
{
printf("nAddress : %u",&x[i]);
printf("nElement : %d",x[i]);
printf("nElement : %u",*(x+i));
printf("nElement : %d",i[x]);
printf("nElement : %d",*ptr);
}
return 0;
}

6. Pointers and Functions:
 Pointers can be used to pass addresses of variables to called functions ,
thus allowing the called function to alter the value stored there .
 It did not change the values stored in the main program because only
the value were passed to the function swap . This is known as “ call by
value ”
 If instead of passing the values of the variables to the called function ,
we pass their addresses , so that the called function can change the
values stored in the calling routine . This known as ” call by reference ” .

7. Pointers with Functions(example):
#include<stdio.h>
void display();
int main()
{
void *(*ptr)();
ptr = &display;
(*ptr)();
return(0);
}
void display()
{
printf("Hello World");
}

8. Pointer Arithmetic
#include<stdio.h>
Void main () {
int a [5]={1,2,3,4,5},b,* pt ;
Pt =&a[0];
Pt =pt+4;
B=a[0];
B+=4;
}
When an integer is added or subtracted from a pointer , the new
pointer value is changed by the integer times the number of bytes in
the data variable the pointer is pointing to .

9. Thank you