What is the difference between tail recursion and head recursion?

What is the difference between tail recursion and head recursion?

Tail recursion is when the recursive call is the last operation in the function, while head recursion is when it occurs at the beginning.

Can you give me an example of each?

Sure! In tail recursion, a function calls itself at the end, like calculating factorial. In head recursion, it processes the recursive call first, like traversing a tree.

Which one is more efficient?

Tail recursion is generally more efficient because it can be optimized by the compiler to avoid increasing the call stack.

Are there any languages that support tail call optimization?

Yes, languages like Scheme, Haskell, and some implementations of JavaScript support tail call optimization.