What is the primary purpose of using functions in C programming?
Answer: A
Functions allow code reusability, modularity, and easier maintenance. They break down complex problems into smaller, manageable pieces.
Q.2Easy
Which keyword is used to define a function in C?
Answer: C
In C, functions are defined by specifying the return type followed by the function name and parameters. No specific 'function' keyword is used.
Q.3Easy
Which of the following is a correct function declaration?
Answer: A
Function declaration syntax is: return_type function_name(parameter_list);
Q.4Easy
What will be the output of the following code?
int func(int x) { return x * 2; }
int main() { printf("%d", func(5)); }
Answer: B
func(5) returns 5 * 2 = 10, which is then printed.
Q.5Easy
How many times can a function be called in a C program?
Answer: C
A function can be called as many times as needed within a program, limited only by memory and stack constraints.
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Q.6Easy
What is the return type of the strlen() function in C?
Answer: B
strlen() returns size_t, which is an unsigned integer type used to represent sizes and counts in C.
Q.7Easy
What is the scope of a function parameter in C?
Answer: C
Function parameters have function scope, meaning they are accessible throughout the entire function body.
Q.8Easy
Which keyword is used to create a function that can be expanded inline by the compiler without actual function call overhead?
Answer: C
The 'inline' keyword (introduced in C99) suggests to the compiler to replace function calls with actual code, reducing call overhead.
Q.9Easy
Consider: int func(int x) { return ++x; } What is the difference if we use x++ instead of ++x?
Answer: B
Pre-increment (++x) increments and returns the new value, while post-increment (x++) increments but returns the old value.
Q.10Easy
What is the output of: int add(int a, int b) { int result = a + b; return result; } If called as add(5, 3)?
Answer: A
The function simply adds two integers and returns their sum, which is 5 + 3 = 8.
Q.11Easy
What will be the output?
int func(int *p) { return *p; }
int main() { int x = 10; printf("%d", func(&x)); }
Answer: A
The function receives a pointer to x, dereferences it with *p, and returns the value 10.
Q.12Easy
In the context of recursion, which of the following is essential to avoid infinite recursion?
Answer: B
A base case is essential in recursive functions to provide a termination condition, otherwise the function will recurse infinitely.
Q.13Easy
Which storage class specifier allows a function to be called only within the file where it is defined?
Answer: A
The static keyword restricts function scope to the file in which it is declared, preventing external linkage.
Q.14Easy
What is the return type of a function that performs an action but doesn't return any value?
Answer: B
The void keyword is used as return type for functions that do not return any value.
Q.15Easy
In C, what happens when a function is called before its declaration?
Answer: B
C requires function declaration before use (forward declaration or definition). Calling without prior declaration causes compilation error in modern C standards.
Q.16Easy
Which of the following is an example of call by value in C?
Answer: B
Call by value passes a copy of the variable. Changes inside the function don't affect the original variable. Option B demonstrates this principle.
Q.17Easy
What is the main difference between function declaration and function definition?
Answer: A
Declaration (prototype) informs compiler about function signature; definition provides the actual implementation body.
Q.18Easy
What is the primary purpose of function prototypes in C?
Answer: A
Function prototypes inform the compiler about function name, return type, and parameters before the actual definition, enabling proper type checking during compilation.
Q.19Easy
Which of the following is a valid function declaration in C?
Answer: A
The correct syntax is return_type function_name(parameters). Option A follows proper C syntax with int as return type, func as name, and void indicating no parameters.
Q.20Easy
What happens when a function is called without a return statement reaching the end?
Answer: B
If a non-void function doesn't explicitly return a value, it returns whatever garbage value happens to be in the return register, leading to undefined behavior.
