Basic C interview questions

1)How do we check whether a linked list is circular?

2)What is the output of this program?

#include
##include
main()
{
typedef union
{
int a;
char b[10];
float c;
}
Struct;

Struct x,y = {100};
x.a = 50;
strcpy(x.b,"hello");
x.c = 21.50;

printf("Union x : %d %s %f \n",x.a,x.b,x.c );
printf("Union y : %d %s %f \n",y.a,y.b,y.c);
}

3)What is a Null object?

4)Name some pure object oriented languages.

5)What is a container class? What are the different types of container classes?

6)What will be the output of the following program:
#include
main()
{
printf("%x",-1<<4);
}

7)What are the major differences between C and C++?

8)What is an incomplete type?

9)What are printf and scanf, call by reference or call by value?

10)What is a const pointer?

11)When should a type cast be used and when should it not be used?

12)Which is the easiest sorting method?

13)Which is the quickest sorting method?

14)Which are the best sorting algorithms to sort a linked list?

15)What is a preprocessor and what will it do for a program?

16)How can a string be converted into a number?

17)How can a number be converted into a string?

18)What is a heap?

19)Why does n++ execute much faster than n+1?

20)What is modular Programming?

21)Which expression always returns true and which expression always returns false?

22)What is the difference between "malloc" and "calloc"?

23)Is C
a)A low level language
b)A middle level language
c)A high level language ?

24)Why doesn't C support function overloading?

25)What is the difference between global int & static int declaration?