Practice Top 30 C Programming Questions on Function

Practice Top 30 C Programming Questions on Function

Q1. Write a function to add two numbers and return the result.

Input: 5 10  
Output: 15  

Q2. Create a function that takes an integer and returns its square.

Input: 7  
Output: 49  

Q3. Write a function to convert a Fahrenheit temperature to Celsius.

Input: 98.6  
Output: 37.00

Q4. Write a function to check if a number is even or odd.

Input: 9  
Output: Odd  

Q5. Write a function to find the maximum of two numbers.

Input: 3 8  
Output: 8

Q6. Write a function to calculate the factorial of a given number.

Input: 5  
Output: 120

Q7. Write a function to swap two numbers without using a temporary variable.

Input: 4 7  
Output: 7 4

Q8. Write a function to find the smallest among three numbers.

Input: 5 3 8  
Output: 3

Q9. Write a function to calculate simple interest based on principal, rate, and time.

Input: 1000 5 2  
Output: 100

Q10. Write a function to check if a given character is a vowel.

Input: a  
Output: Vowel

Q11. Write a function to reverse a number.

Input: 1234  
Output: 4321

Q12. Write a function to check whether a number is prime or not.

Input: 7  
Output: Prime

Q13. Write a function to calculate the sum of digits of a number.

Input: 123  
Output: 6

Q14. Write a function to find the greatest common divisor (GCD) of two numbers.

Input: 12 15  
Output: 3

Q15. Write a function to calculate \( a^b \) (a raised to the power b).

Input: 2 3  
Output: 8

Q16. Write a function to check if a number is a palindrome.

Input: 121  
Output: Palindrome

Q17. Write a function to find the length of a given string.

Input: Hello  
Output: 5

Q18. Write a function to check if a number is an Armstrong number.

Input: 153  
Output: Armstrong

Q19. Write a function to count the number of vowels in a string.

Input: Education  
Output: 5

Q20. Write a function to calculate the area of a circle given its radius.

Input: 7  
Output: 153.94

Q21. Write a function to generate the first N Fibonacci numbers.

Input: 5  
Output: 0 1 1 2 3

Q22. Write a function to check if a year is a leap year.

Input: 2020  
Output: Leap Year

Q23. Write a function to find the sum of elements in an array.

Input: 1 2 3 4 5  
Output: 15

Q24. Write a function to check if a number is a perfect number.

Input: 28  
Output: Perfect

Q25. Write a function to find the largest element in an array.

Input: 3 1 4 1 5  
Output: 5

Q26. Write a function to reverse a string.

Input: Hello  
Output: olleH

Q27. Write a function to count the number of words in a string.

Input: Hello World  
Output: 2

Q28. Write a function to check if a number is a perfect square.

Input: 16  
Output: Perfect Square

Q29. Write a function to find the sum of the first N natural numbers.

Input: 10  
Output: 55

Q30. Write a function to check if a number is positive.

Input: -5  
Output: Negative