C Preprocessor MCQs

Question 1

What is the purpose of the C preprocessor in C programming?

Accepted Answer

Preprocess code before compilation

Answer

Compile C code

Answer

Optimize code

Answer

Execute code

Question 2

Which directive is used to include the contents of another file in a C program using the C preprocessor?

Accepted Answer

#include

Answer

#define

Answer

#ifdef

Answer

#pragma

Question 3

What is the purpose of the #define directive in C preprocessing?

Accepted Answer

To define a macro

Answer

To include a header file

Answer

To declare a constant

Answer

To declare a variable

Question 4

In C, which directive is used to conditionally include code based on preprocessor macros?

Accepted Answer

#if

Answer

#ifdef

Answer

#ifndef

Answer

#else

Question 5

What is the result of the #ifdef DEBUG directive if the DEBUG macro is defined?

Accepted Answer

The code block following it is included

Answer

The code block following it is excluded

Answer

It generates a compilation error

Answer

It defines the DEBUG macro

Question 6

Which directive in C preprocessing is used to define a macro with parameters?

Accepted Answer

#define

Answer

#ifdef

Answer

#include

Answer

#if

Question 7

In C preprocessing, what is the purpose of the #undef directive?

Accepted Answer

To undefine a macro

Answer

To include a header file

Answer

To define a macro

Answer

To declare a variable

Question 8

What does the #ifndef directive do in C preprocessing?

Accepted Answer

Checks if a macro is not defined

Answer

Checks if a macro is defined

Answer

Checks if a variable is declared

Answer

Checks if a function is defined

Question 9

In C, what does the #pragma directive do in C preprocessing?

Accepted Answer

Provides compiler-specific instructions

Answer

Includes a header file

Answer

Defines a macro

Answer

Checks for syntax errors