Dynamic Memory Allocation in C

What are Pointers in C

It is a variable which is used to store the address of another variable.

Advantages of pointer

• Return multiple values from function
• Access any memory location
• Improves the performance
• Reduces the code
• Used for dynamic memory allocation
• Used in arrays, functions and structures

Example

#include <stdio.h>
#include <conio.h>
void main(){
clrscr();
int n=50;
int *p;    //declaration of pointer
p=&n; //stores the address of number variable
printf("Address of n variable is %x n",&n);
printf("Address of p variable is %x n",p);
printf("Value of p variable is %d n",*p);
getch();
}

Output
Address of n variable is fff4
Address of p variable is fff4
Value of p variable is 50

Dynamic memory allocation in C

Dynamic memory allocation means to allocate the memory at run time. Dynamic memory allocation is possible by 4 functions of stdlib.h header file.

1. malloc()
2. calloc()
3. realloc()
4. free()