Coding challenges to help improve your programming logic skills.

Array Sum: Write a function to calculate the sum of all the elements in an array.

Palindrome Check: Write a function to check if a string is a palindrome.

List Sorting: Implement a sorting algorithm (such as bubble sort, selection sort, or merge sort) to sort a list of numbers.

Fibonacci: Write a function to calculate the nth term of the Fibonacci sequence.

Recursive Factorial: Write a recursive function to calculate the factorial of a number.