Dynamic Memory Allocation

Module 1: Dynamic Memory Allocation

• malloc()

• calloc()

• realloc()

• free()

realloc() Dynamic Memory Allocation

Dynamic Memory Allocation: realloc() 

Download the Program
Syntax:
ptr = (cast_type *)realloc(ptr, newsize_in_bytes);

#include<stdio.h>
void main()
{

       char *str;
       str = (char *)malloc(10);

       if(str == NULL)
      {
          printf("\nInsufficient memory allocation");
          exit(0);
      }

      strcpy(str, "hello");
      printf("\nString is = %s", str);

      str = (char  *)realloc(str, 20);

      if(str == NULL)
      {
          printf("\nInsufficient memory allocation");
          exit(0);
      }

      strcpy(str, "how are you");
      printf("\nString is = %s", str);
      free(str);
}

Output:
String is = hello
String is = how are you

Also Check,
https://tejaswinihbhat.blogspot.in/2016/08/dynamic-memory-allocation.html
https://tejaswinihbhat.blogspot.in/2016/08/malloc-dynamic-memory-allocation.html
https://tejaswinihbhat.blogspot.in/2016/08/calloc-dynamic-memory-allocation.html
https://tejaswinihbhat.blogspot.in/2016/08/realloc-dynamic-memory-allocation.html

calloc() Dynamic Memory Allocation

Dynamic Memory Allocation: calloc()

Download the Program

Syntax:

ptr = (cast_type  *) calloc (number_of_blocks, size_in_bytes);

#include<stdio.h>

void main()

{

    int i,n;

    int *arr;

    printf("\nEnter the number of elements: ");

    scanf("%d", &n);

    arr = (int *)calloc(n, sizeof(int));

    if(arr == NULL)

    {

        printf("\nInsufficient memory allocation");

        exit(0);

    }

    printf("\nEnter the array elements: ");

    for(i=0; i<n; i++)

        scanf("%d", (arr+i));

    printf("\nThe array elements are: ");

    for(i=0; i<n; i++)

        printf("%d ", *(arr+i));

     free(arr);

}

Output:

Enter the number of elements: 5

Enter the array elements: 11    22     33    44    55

The array elements are: 11    22    33    44    55

Also Check,
https://tejaswinihbhat.blogspot.in/2016/08/dynamic-memory-allocation.html
https://tejaswinihbhat.blogspot.in/2016/08/malloc-dynamic-memory-allocation.html
https://tejaswinihbhat.blogspot.in/2016/08/calloc-dynamic-memory-allocation.html
https://tejaswinihbhat.blogspot.in/2016/08/realloc-dynamic-memory-allocation.html

malloc() Dynamic Memory Allocation

Dynamic Memory Allocation: malloc()

Download the Program

Syntax:
ptr = (cast_type *) malloc(size_in_bytes);


#include<stdio.h>
void main()
{
        int i, n;
        int *arr;

        printf("\nEnter the number of elements: ");
        scanf("%d", &n);

        arr = (int *)malloc(n*sizeof(int));

        if(arr == NULL)
        {
            printf("\nInsufficient memory allocation");
            exit(0);
        }

        printf("\nEnter the array elements: ");
        for(i=0; i<n; i++)
            scanf("%d", (arr+i));

        printf("\nThe array elements are: ");
        for(i=0; i<n; i++)
            printf("%d ", *(arr+i));

        free(arr);
}

Output:
Enter the number of elements: 5
Enter the array elements: 11    22    33     44    55
The array elements are: 11    22    33    44    55


Also Check,
https://tejaswinihbhat.blogspot.in/2016/08/dynamic-memory-allocation.html
https://tejaswinihbhat.blogspot.in/2016/08/malloc-dynamic-memory-allocation.html
https://tejaswinihbhat.blogspot.in/2016/08/calloc-dynamic-memory-allocation.html
https://tejaswinihbhat.blogspot.in/2016/08/realloc-dynamic-memory-allocation.html

Data Structures and Applications(15CS33): Module 1

Data Structures and Applications (15CS33):

Module 1

Click on the respective topics: 

• Structures

• Unions

• Pointers

• Arrays

• Strings

• Dynamic Memory Management