What are the differences between tail recursion and head recursion?

What are the differences between tail recursion and head recursion?

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

Can you give me an example of each?

Sure! In tail recursion, a function calls itself at the end, like this: function tailRec(n) { return n === 0 ? 1 : n * tailRec(n - 1); }. In head recursion, it looks like this: function headRec(n) { if (n === 0) return 1; return headRec(n - 1) * n; }.

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, while head recursion can lead to stack overflow for large inputs.