C Programming - MCQ Practice Questions

C does not have a 'ref' keyword like C++. Pointers are used to achieve pass-by-reference semantics in C by passing the address of a variable.

A base case is essential in recursive functions to provide a stopping condition. Without it, the function will cause stack overflow. The base case ensures recursion terminates properly.

When const is applied to a function parameter, it prevents modification of that parameter within the function body, making it immutable for the duration of the function.

extern functions have external linkage and can be accessed from other translation units. It's the default linkage for functions declared outside a file.

Function pointers enable polymorphism by allowing runtime selection of which function to call. They are crucial for implementing callbacks and dynamic function dispatch.

The C standard does not specify the order of evaluation of function arguments. The order is implementation-dependent and can vary between compilers.

A declaration tells the compiler about the function's signature (return type, name, parameters); a definition provides the actual implementation (function body).

The restrict keyword informs the compiler that the pointer is the sole means of accessing the data it points to, allowing for optimization. It's a hint for compiler optimization.

C provides multiple methods to return values: structs for encapsulation, pointers for indirect modification, and global variables (though not recommended). All three are technically valid approaches.

If a function is declared but not defined, the compiler generates code to call it (compilation succeeds), but the linker fails to find the function definition, resulting in a linker error.

When an array is passed to a function, it decays to a pointer to its first element. This means modifications to array elements affect the original array outside the function.

Inlining substitutes a function call with the actual function body at compile time, eliminating function call overhead. This is a compiler optimization for performance-critical code.

Variadic functions must have at least one fixed parameter before the ellipsis (...). This allows the function to know where variadic arguments begin. Type checking is NOT enforced for variadic arguments.

A callback is a function pointer passed to another function, which then invokes it at some point. Callbacks are essential for event-driven programming and implementing custom behavior.

When an array is used as a function parameter, it undergoes array-to-pointer decay, converting to a pointer to the first element. This is why size information is lost.

All three approaches are valid for error handling in C. Functions typically return NULL for pointers, negative values for integers, or use predefined error codes to indicate failure states.

In C, arrays decay to pointers when passed to functions, meaning the address is passed. Any modifications through the pointer affect the original array. This is effectively pass-by-reference behavior for arrays.

A void function cannot return a value. Attempting to assign the return value of a void function to a variable will cause a compilation error in standard C compilers.

Without a base case, recursion never terminates. Each function call pushes data onto the stack. Eventually, the stack memory is exhausted, causing a stack overflow error. This is a runtime error, not a compile-time error.