C Programming Questions and Answers – Conditional Inclusion

C Programming Questions and Answers – Conditional Inclusion

1.What is the output of this C code?

#include <stdio.h>

#define SYSTEM 20

int main()

{

int a = 20;

#if SYSTEM == a

printf(“HELLO “);

#endif

#if SYSTEM == 20

printf(“WORLD\n”);

#endif

}

a) HELLO

b) WORLD

c) HELLO WORLD

d) No Output

2.Comment on the following code?

#include <stdio.h>

#define Cprog

int main()

{

int a = 2;

#ifdef Cprog

a = 1;

printf(“%d”, Cprog);

}

a) No output on execution

b) Output as 1

c) Output as 2

d) Compile time error

3.The “else if” in conditional inclusion is written by?

a) #else if

b) #elseif

c) #elsif

d) #elif

4.What is the output of this C code?

#include <stdio.h>

#define COLD

int main()

{

#ifdef COLD

printf(“COLD\t”);

#undef COLD

#endif

#ifdef COLD

printf(“HOT\t”);

#endif

}

a) HOT

b) COLD

c) COLD HOT

d) No Output

5.Which of the following sequences are unaccepted in C language?

a) #if

#else

#endif

b) #if

#elif

#endif

c) #if

#if

#endif

d) #if

#undef

#endif

6.In a conditional inclusion, if the condition that comes after the if holds.

a) Then the code up to the following #else or #elif or #endif is compiled

b) Then the code up to the following #endif is compiled even if #else or #elif is present

c) Both a & b

d) None of the mentioned

7.Conditional inclusion can be used for

a) Preventing multiple declarations of a variable

b) Check for existence of a variable and doing something if it exists

c) Preventing multiple declarations of same function

d) All of the mentioned

8.The #elif directive cannot appear after the preprocessor #else directive.

a) true

b) false

c) None of the mentioned

d) Varies

9.For each #if, #ifdef, and #ifndef directive.

a) There are zero or more #elif directives

b) Zero or one #else directive

c) One matching #endif directive

d) All of the mentioned

10.The #else directive is used for

a) Conditionally include source text if the previous #if, #ifdef, #ifndef, or #elif test fails.

b) Conditionally include source text if a macro name is not defined

c) Conditionally include source text if a macro name is defined

d) Ending conditional text

11.What is the output of this C code?

#include <stdio.h>

#define MIN 0

#if MIN

#define MAX 10

#endif

int main()

{

printf(“%d %d\n”, MAX, MIN);

return 0;

}

a) 10 0

b) Compile time error

c) Undefined behaviour

d) None of the mentioned

12.What is the output of this C code?

#include <stdio.h>

#define MIN 0

#ifdef MIN

#define MAX 10

#endif

int main()

{

printf(“%d %d\n”, MAX, MIN);

return 0;

}

a) 10 0

b) Compile time error

c) Undefined behaviour

d) None of the mentioned

13.What is the output of this C code?

#include <stdio.h>

#define MIN 0

#if defined(MIN) + defined(MAX)

#define MAX 10

#endif

int main()

{

printf(“%d %d\n”, MAX, MIN);

return 0;

}

a) 10 0

b) Compile time error

c) Undefined behaviour

d) Somegarbagevalue 0

14.What is the output of this C code?

#include <stdio.h>

#define MIN 0

#if defined(MIN) – (!defined(MAX))

#define MAX 10

#endif

int main()

{

printf(“%d %d\n”, MAX, MIN);

return 0;

}

a) 10 0

b) Compile time error

c) Undefined behaviour

d) Somegarbagevalue 0

15.What is the output of this C code?

#include <stdio.h>

#define MIN 0

#ifdef(MIN)

#define MAX 10

#endif

int main()

{

printf(“%d %d\n”, MAX, MIN);

return 0;

}

a) 10 0

b) Compile time error

c) Both b and c

d) Preprocessor error

16.What is the output of code given below?

#include <stdio.h>

#define MIN 0);

#ifdef MIN

#define MAX 10

#endif

int main()

{

printf(“%d %d\n”, MAX, MIN

return 0;

}

a) 10 0

b) Compile time error due to illegal syntax for printf

c) Undefined behaviour

d) Compile time error due to illegal MIN value