Example to understand DMA in C programming

#include <stdio.h>

#include <conio.h>

#include <stdlib.h>

void mallocExample();

void callocExample();

void reallocExample();

void main()

{

    mallocExample();

    callocExample();

    reallocExample();

    getch();

}

void mallocExample()

{

    int n,*ptr,i;

    printf("MALLOC\nEnter how many space wanna reserve for int:: ");

    scanf("%d",&n);

    ptr=(int*)malloc(n*sizeof(int));

    printf("Reserved memories and default values are:\n");

    for(i=0;i<n;i++)

        printf("%u\t%d\n",ptr+i,*(ptr+i));

    free(ptr);

}

void callocExample()

{

    int n,*ptr,i;

    printf("\n\nCALLOC\nEnter how many space wanna reserve for int:: ");

    scanf("%d",&n);

    ptr=(int*)calloc(n,sizeof(int));

    printf("Reserved memories and default values are:\n");

    for(i=0;i<n;i++)

        printf("%u\t%d\n",ptr+i,*(ptr+i));

    free(ptr);

}

void reallocExample()

{

    int n1,n2,*ptr,i;

    printf("\n\nREALLOC\nEnter how many space wanna reserve for int:: ");

    scanf("%d",&n1);

    ptr=(int*)calloc(n1,sizeof(int));

    printf("Reserved memories and default values are:\n");

    for(i=0;i<n1;i++)

        printf("%u\t%d\n",ptr+i,*(ptr+i));

    free(ptr);

    printf("Enter new size:: ");

    scanf("%d",&n2);

    realloc(ptr,n2);

    printf("Again, Reserved memories and default values are:\n");

    for(i=0;i<n2;i++)

        printf("%u\t%d\n",ptr+i,*(ptr+i));

    free(ptr);

}

OUTPUT:

C Program to Find the Number of Characters in a String >>