1. Write a function to find the maximum number in an array.

2. Write a function to find the minimum number in an array.

3. Implement a function to calculate the sum of all elements in an array.

4. Write a function to count the number of even numbers in an array

5. Implement a function to count the number of odd numbers in an array.

6. Write a function to reverse an array.

7. Implement a function to find the average of elements in an array.

8. Write a function to check if a given element exists in an array.

9. Implement a function to find the index of a given element in an array.

10. Write a function to find the second largest number in an array.

11. Implement a function to remove duplicates from an array.

12. Write a function to sort an array in ascending order.

13. Implement a function to sort an array in descending order.

14. Write a function to find the median of an array.

15. Implement a function to merge two arrays into one.

16. Write a function to rotate an array to the right by one position.

17. Implement a function to rotate an array to the left by one position.

18. Write a function to find the intersection of two arrays.

19. Implement a function to find the union of two arrays.

20. Write a function to find the difference between two arrays.

21. Implement a function to find the maximum product of two numbers in an array.

22. Write a function to find the common elements in three arrays.

23. Implement a function to move all zeros to the end of an array.

24. Write a function to move all zeros to the beginning of an array.

25. Implement a function to separate even and odd numbers in an array.

26. Write a function to find the frequency of each element in an array.

27. Implement a function to remove a given element from an array.

28. Write a function to check if two arrays are equal.

29. Implement a function to find the missing number in an array of consecutive numbers.

30. Write a function to find the duplicate number in an array of integers.