What is recursive behavior?

Execution of code or functions that call themselves.

Main elements:

• Base case: The condition under which recursion stops. Without it, infinite recursion occurs.
• Recursive case: Part of the function where it calls itself, usually with a modified argument.

Example (calculating factorial):

func factorial(_ n: Int) -> Int {
    // Base case
    if n <= 1 {
        return 1
    }
    // Recursive case
    return n * factorial(n - 1)
}
// Example call
let result = factorial(5) // 120

Advantages:

• Elegant solution for problems with a self-similar structure (e.g., tree traversal).
• More readable code in some cases.

Disadvantages:

• Can consume a lot of memory (call stack).
• Stack overflow possible with too deep recursion.
• Sometimes less efficient than iterative solutions.