C Dynamic Memory Allocation Test – 1

1. The following C code is an example of __________

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
main()
{
    char *p,*q;
    p=(char*)malloc(3*sizeof(char));
    q=p;
    strcpy(p,"hello");
    printf("p=%s",p);
    printf("q=%s",q);
    free(q);
    q=NULL;
    gets(p);
    gets(q);
    printf("%s",p);
    printf(“%s”,q);
}

2. What will happens if the statement free(a) is removed in the following C code?

#include<stdio.h>
#include<stdlib.h>
main()
{
    int *a;
    a=(int*)malloc(sizeof(int));
    *a=100;
    printf("*a%d",*a);
    free(a);
    a=(int*)malloc(sizeof(int));
    *a=200;
    printf("a%p",a);
    *a=200;
    printf("a%d",*a);
}

3. Which of the following functions allocates multiple blocks of memory, each block of the same size?

4. In the function malloc(), each byte of allocated space is initialized to zero.

5. In the function realloc(), if the new size of the memory block is larger than the old size, then the added memory ___________

6. A condition where in memory is reserved dynamically but not accessible to any of the programs is called _____________

7. The incorrect statement with respect to dangling pointers is ___________

8. What will be the output of the following C code?

#include<stdio.h>
#include<stdlib.h>
void main()
{
    char *p = calloc(100, 1);
    p = "welcome";
    printf("%s\n", p);
}

9. The free() function frees the memory state pointed to by a pointer and returns ___________

10. What will be the output of the following C code if the input entered as first and second number is 5 and 6 respectively?

#include<stdio.h>
#include<stdlib.h>
main()
{
    int *p;
    p=(int*)calloc(3*sizeof(int));
    printf("Enter first number\n");
    scanf("%d",p);
    printf("Enter second number\n");
    scanf("%d",p+2);
    printf("%d%d",*p,*(p+2));
    free(p);
}