Functions Interview Questions

    Question 1: Purpose of Functions

    What is the main advantage of using functions in C?

    Question 2: Built-in Functions

    Which of the following is a standard library function in C?

    Question 3: Function Declaration

    Where is a function prototype (declaration) usually placed in a C program?

    Question 4: Return Type

    What does a function return if its return type is not specified in C (default)?

    Question 5: Function with Parameters

    What will be the output?

    #include <stdio.h>

int add(int a, int b) {
    return a + b;
}

int main() {
    printf("%d", add(3, 4));
    return 0;
}

    Question 6: Function Call by Value

    What will be printed?

    #include <stdio.h>

void change(int x) {
    x = 100;
}

int main() {
    int a = 5;
    change(a);
    printf("%d", a);
    return 0;
}

    Question 7: Recursive Function

    Which of the following functions is an example of recursion?

    Question 8: Recursion Example

    What is the output of the following code?

    #include <stdio.h>

int fact(int n) {
    if (n == 0) return 1;
    return n * fact(n - 1);
}

int main() {
    printf("%d", fact(3));
    return 0;
}

    Question 9: Standard Library Header

    Which header file must be included to use sqrt() function?

    Question 10: Void Functions

    What is true about a void function in C?