C programs post1

Q1.)

#include
#define TOTAL_ELEMENTS (sizeof(array) / sizeof(array[0]))
int array[] = {23,34,12,17,204,99,16};

int main()
{
signed int d;
printf("Total Elements in the array are => %d\n",TOTAL_ELEMENTS);
for(d=-1;d <= (TOTAL_ELEMENTS-2);d++)
printf("%d\n",array[d+1]);
printf("Did u see the output..");
return 0;
}


Q 2.) File1.c 1 int arr[80]; File2.c extern int *arr;
int main()
{
arr[1] = 100;
return 0;
}
what should be the output..


Q 3.) #include
int main()
{
int a=1;
switch(a)
{ int b=20;
case 1: printf("b is %d\n",b);
break;
default:printf("b is %d\n",b);
break;
}
return 0;
}



Q.4)
#include
#include
void Error(char* s)
{
printf(s);
return;
}

int main()
{
int *p;
p = (int*)malloc(sizeof(int));
if(!p)
{
Error("memory error");
Error("Quitting....\n");
exit(1);
}
else
{
/*some stuff to use p*/
}
free(p);
return 0;
}

Find potential problem with the error function.. a security concern..






Q 5.)
Easy..
#include
int main()
{
char c;
scanf("%c",&c);
printf("%c\n",c);
scanf(" %c",&c);//see space before %c
printf("%c\n",c);

return 0;
}

why this runs perfect..
but fails in this program..

#include
int main()
{
char c;
scanf("%c",&c);
printf("%c\n",c);
scanf("%c",&c);//no space this time..
printf("%c\n",c);

return 0;
}

Even though we know that white spaces are ignored..
which include space, newline and tab..
so why the second time output is not desired..