MCQs on Embedding Lua in Applications | Lua

Topic 1: Lua as a Scripting Engine

1. What is Lua primarily used for in an application?
   a) Operating System Management
   b) Data processing
   c) Scripting engine for embedding
   d) Memory management
2. What does Lua provide when embedded in an application?
   a) Visual UI components
   b) Lightweight, fast scripting
   c) Network communication
   d) Database management
3. What is a key advantage of using Lua as a scripting engine?
   a) It is highly resource-heavy
   b) It is lightweight and fast
   c) It requires a lot of system memory
   d) It does not support dynamic types
4. Lua is known for which of the following features?
   a) Extensible syntax
   b) Being a standalone application
   c) Poor integration with other languages
   d) Having a complex data model
5. In what type of applications is Lua commonly embedded?
   a) Game engines
   b) Video editing software
   c) Cloud applications
   d) Antivirus software
6. Which of the following is a primary use case for Lua embedded in applications?
   a) High-performance computation
   b) Enabling flexible and customizable user actions
   c) Low-level hardware programming
   d) Creating new programming languages
7. How does Lua handle memory management when embedded?
   a) Manual memory management
   b) Automatic garbage collection
   c) Static memory allocation
   d) User-controlled memory pools

Topic 2: Communicating Between Lua and Host Languages (C, C++)

8. How do you interface Lua with C or C++?
   a) Using a Lua-specific compiler
   b) Through the Lua C API
   c) By modifying Lua’s core
   d) By using a built-in function in Lua
9. What is the role of the Lua C API in communication between Lua and C?
   a) It compiles Lua code
   b) It allows C code to invoke Lua functions and vice versa
   c) It manages Lua’s memory
   d) It generates Lua bytecode
10. Which of the following is used to push C function results to Lua?
    a) lua_pushstring()
    b) lua_pushvalue()
    c) lua_pushnumber()
    d) lua_pushcfunction()
11. What is the purpose of lua_getglobal in Lua-C communication?
    a) To push a Lua function onto the stack
    b) To retrieve a global Lua variable into C
    c) To execute Lua scripts
    d) To call C functions from Lua
12. Which data types are compatible between C and Lua for function calls?
    a) Only integer types
    b) Only string types
    c) Lua’s basic types map to C types
    d) Lua supports complex C data types directly
13. When passing data between Lua and C, which of the following is true?
    a) Only integers can be passed
    b) Lua objects must be converted to C types
    c) C types automatically convert to Lua types
    d) No data can be passed between Lua and C
14. How is an error handled in Lua when called from C?
    a) Lua ignores errors
    b) The error is propagated to C through a callback
    c) Lua throws a custom error message
    d) C returns an error code
15. What is required to compile Lua code into a C program?
    a) Lua-specific compiler
    b) Modifying the Lua core files
    c) Lua library linking and a Lua interpreter
    d) No compilation needed
16. What is the main advantage of embedding Lua in C/C++ programs?
    a) It reduces application performance
    b) It allows dynamic configuration without recompiling
    c) It simplifies UI development
    d) It eliminates memory management issues
17. How is Lua code executed from C/C++?
    a) By using a system call
    b) By embedding Lua interpreter in the application
    c) By compiling Lua code into machine language
    d) Lua code is interpreted directly by C

Topic 3: Writing C Functions Callable from Lua

18. How do you make C functions callable from Lua?
    a) Use lua_call function
    b) Use lua_register function
    c) Directly embed C code into Lua
    d) Define C functions in Lua scripts
19. Which function is used in C to register a C function so that it can be called from Lua?
    a) lua_pushcfunction()
    b) lua_register()
    c) lua_getglobal()
    d) lua_call()
20. In which format are C functions passed when called from Lua?
    a) As raw memory pointers
    b) In Lua’s native bytecode format
    c) As arguments on the Lua stack
    d) As external files
21. What does luaL_checknumber do when called from Lua?
    a) Converts C values to Lua types
    b) Ensures the argument is a valid number
    c) Executes a Lua script
    d) Allocates memory for Lua data
22. How can a C function return multiple values to Lua?
    a) By using an array
    b) By using a table
    c) By pushing values onto the Lua stack
    d) By returning a tuple
23. What is the effect of lua_pushcfunction in Lua-C communication?
    a) It pushes a Lua function onto the stack
    b) It pushes a C function onto the Lua stack
    c) It executes a C function
    d) It calls a Lua function from C
24. Which of the following is necessary for calling C functions in Lua?
    a) Linking Lua interpreter with the C program
    b) Using a Lua compiler
    c) Calling Lua functions from C using system calls
    d) Defining Lua code within the C program
25. How does the lua_pcall function differ from lua_call?
    a) lua_pcall includes error handling
    b) lua_call calls a Lua function directly
    c) lua_pcall is used only for C functions
    d) There is no difference
26. Which of the following is an example of how to register a C function in Lua?
    a) lua_register(L, "function_name", my_function)
    b) lua_pushcfunction(L, my_function)
    c) lua_add_function(L, "my_function")
    d) lua_call(L, my_function)
27. How does Lua handle calling a C function that returns an integer?
    a) By directly calling the C function
    b) By pushing the result to the Lua stack
    c) By returning the result as a string
    d) By executing the result as a new Lua function
28. What happens if a C function returns a type that Lua cannot handle?
    a) Lua automatically converts the type
    b) Lua throws an error
    c) The program crashes
    d) The return value is ignored
29. Can C functions in Lua interact with Lua tables?
    a) No, they only work with basic types
    b) Yes, using Lua’s C API to access tables
    c) Only if tables are passed as arguments
    d) No, C functions cannot access Lua tables
30. What is the result of calling luaL_ref in Lua from C?
    a) Registers a function as a Lua object
    b) Stores a Lua object in a reference table
    c) Calls a Lua function from C
    d) Removes a function from the Lua stack

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