C Programming Questions and Answers

Which header file should be included to use functions like malloc() and calloc()?

What will be the output of the program?

#include < stdio . h >#include < stdlib . h >int main()
{
    int *p;
    p = (int *) malloc (20); /* Assume p has address of 1314 */free(p);
    printf("%u", p);
    return0;
}

What will be the output of the program (16-bit platform)?

#include < stdio . h >#include < stdlib . h >int main()
{
    int *p;
    p = (int *) malloc (20);
    printf("%d\n", sizeof (p));
    free(p);
    return0;
}

What will be the output of the program?

#include < stdio . h >#includeint main()
{
    char *s;
    char *fun();
    s = fun();
    printf("%s\n", s);
    return0;
}
char *fun()
{
    char buffer[30];
    strcpy(buffer, "RAM");
    return (buffer);
}

Assume integer is 2 bytes wide. What will be the output of the following code?

#include < stdio . h >#include < stdlib . h >#define MAXROW 3#define MAXCOL 4int main()
{
    int (*p)[MAXCOL];
    p = (int (*) [MAXCOL]) malloc( MAXROW *sizeof (*p));
    printf("%d, %d\n", sizeof(p), sizeof(*p));
    return0;
}

How many bytes of memory will the following code reserve?

#include < stdio . h >#include < stdlib . h >int main()
{
    int *p;
    p = (int *)malloc(256 * 256);
    if(p == NULL)
        printf("Allocation failed");
    return0;
}

Point out the error in the following program.

#include#include < stdlib . h >int main()
{
    int *a[3];
    a = (int*) malloc ( sizeof (int) *3);
    free(a);
    return0;
}

Point out the error in the following program.

#include#include < stdlib . h >int main()
{
    char *ptr;
    *ptr = (char)malloc(30);
    strcpy(ptr, "RAM");
    printf("%s", ptr);
    free(ptr);
    return0;
}

How will you free the memory allocated by the following program?

#include#include#define MAXROW 3#define MAXCOL 4int main()
{
    int **p, i, j;
    p = (int **) malloc(MAXROW * sizeof(int*));
    return0;
}