1. Which of the following best describes a structure in C programming?
a) A built-in data type
b) A collection of variables of different data types under one name
c) A special function to manipulate data
d) A reserved keyword for defining loops
Answer: b) A collection of variables of different data types under one name
Explanation: Structures allow grouping together variables of different data types under a single name, facilitating organization and management of related data.
2. How are structure elements accessed in C?
a) Using the arrow (->) operator
b) Using the dot (.) operator
c) Using the asterisk (*) operator
d) Using the percent (%) operator
Answer: b) Using the dot (.) operator
Explanation: Structure elements are accessed using the dot (.) operator followed by the member name.
3. Which statement about the storage of structure elements is true?
a) Each element of a structure is stored in separate memory locations
b) All elements of a structure are stored in contiguous memory locations
c) Structure elements are stored in a random order
d) Structure elements are stored in reverse order
Answer: b) All elements of a structure are stored in contiguous memory locations
Explanation: In memory, structure elements are stored one after the other in contiguous memory locations.
4. What does an array of structure represent in C?
a) A single variable with multiple elements
b) Multiple variables with single elements
c) A collection of structures with identical elements
d) A collection of structures with different elements
Answer: c) A collection of structures with identical elements
Explanation: An array of structure represents a collection of structures where each structure contains the same elements.
5. Which of the following is a feature of the C preprocessor?
a) It is executed at compile time
b) It is executed at runtime
c) It modifies the behavior of the compiler
d) It is responsible for memory allocation
Answer: a) It is executed at compile time
Explanation: The C preprocessor performs text manipulation before the compilation process begins.
6. What does macro expansion refer to in the C preprocessor?
a) Expanding memory allocation
b) Expanding conditional statements
c) Expanding user-defined macros
d) Expanding function definitions
Answer: c) Expanding user-defined macros
Explanation: Macro expansion involves replacing macro identifiers with their corresponding macro bodies throughout the program.
7. What is a file inclusion directive used for in the C preprocessor?
a) Including external libraries
b) Including header files
c) Including function definitions
d) Including conditional statements
Answer: b) Including header files
Explanation: The file inclusion directive (#include) is used to include header files in a C program.
8. Which directive is used for conditional compilation in the C preprocessor?
a) #while
b) #for
c) #if
d) #switch
Answer: c) #if
Explanation: The #if directive allows conditional compilation based on specified conditions.
9. What is the purpose of the #pragma directive in the C preprocessor?
a) To include header files
b) To define macros
c) To provide machine-specific instructions
d) To declare structures
Answer: c) To provide machine-specific instructions
Explanation: The #pragma directive is used to provide machine-specific instructions to the compiler.
10. How is a union defined and declared in C?
a) Using the keyword ‘union’ followed by a list of member variables
b) Using the keyword ‘struct’ followed by a list of member variables
c) Using the keyword ‘typedef’ followed by a list of member variables
d) Using the keyword ‘enum’ followed by a list of member variables
Answer: a) Using the keyword ‘union’ followed by a list of member variables
Explanation: A union is defined and declared using the keyword ‘union’ followed by a list of member variables enclosed in curly braces.
11. How are union members accessed in C?
a) Using the dot (.) operator
b) Using the arrow (->) operator
c) Using the asterisk (*) operator
d) Using the percent (%) operator
Answer: a) Using the dot (.) operator
Explanation: Union members are accessed using the dot (.) operator followed by the member name.
12. What does a union of structures represent in C?
a) A single structure with multiple elements
b) Multiple structures with single elements
c) A collection of structures with identical elements
d) A collection of structures with different elements
Answer: d) A collection of structures with different elements
Explanation: A union of structures represents a collection of structures where each structure may have different elements.
13. How are union members initialized in C?
a) By assigning values to each member separately
b) By using the ‘initialize’ keyword
c) By using the ‘union’ keyword
d) By using the ‘struct’ keyword
Answer: a) By assigning values to each member separately
Explanation: Union members are initialized by assigning values to each member separately.
14. What is a common use of unions in C?
a) To organize related variables
b) To represent different data types in the same memory location
c) To perform mathematical operations
d) To define loops
Answer: b) To represent different data types in the same memory location
Explanation: Unions are often used to allocate memory for different data types in the same memory location.
15. What is the primary purpose of user-defined data types in C?
a) To define built-in data types
b) To define complex data structures
c) To optimize memory allocation
d) To enhance the performance of loops
Answer: b) To define complex data structures
Explanation: User-defined data types are used to create complex data structures that can encapsulate multiple variables and data types.
16. What directive is used to include external files in C programs?
a) #use
b) #insert
c) #include
d) #import
Answer: c) #include
Explanation: The #include directive is used to include external files, typically header files, in C programs.
17. Which directive is used to define macros in C?
a) #define
b) #macro
c) #def
d) #macrodef
Answer: a) #define
Explanation: The #define directive is used to define macros in C programming.
18. What is the purpose of the #undef directive in C?
a) To undefine macros
b) To define macros
c) To include header files
d) To declare structures
Answer: a) To undefine macros
Explanation: The #undef directive is used to undefine macros previously defined using the #define directive.
19. Which directive is used to provide compiler-specific instructions in C?
a) #define
b) #pragma
c) #ifdef
d) #undef
Answer: b) #pragma
Explanation: The #pragma directive is used to provide compiler-specific instructions in C.
20. What is the purpose of using the conditional directives in C preprocessor?
a) To include conditional statements
b) To perform conditional compilation
c) To execute conditional loops
d) To define conditional functions
Answer: b) To perform conditional compilation
Explanation: Conditional directives in the C preprocessor are used to conditionally include or exclude portions of code during compilation based on specified conditions.