Dynamic Memory Allocation in C

Definition:
Dynamic memory allocation allows memory to be allocated during runtime using pointers.

🔹 Functions used (in stdlib.h):

Function	Description
malloc()	Allocates memory block
calloc()	Allocates memory and initializes it to 0
realloc()	Re-allocates memory block
free()	Frees allocated memory

Example – Using malloc():

#include <stdio.h>

#include <stdlib.h>

int main() {

    int *ptr;

    ptr = (int *)malloc(3 * sizeof(int));

    if (ptr == NULL) {

        printf(“Memory not allocated\n”);

        return 1;

    }

    ptr[0] = 10;

    ptr[1] = 20;

    ptr[2] = 30;

    for (int i = 0; i < 3; i++) {

        printf(“%d “, ptr[i]);

    }

    free(ptr); // release memory

    return 0;

}