nthfib.js

// RECURSIVE APPROACH
function fibonacciRecursive(n) {
  if (n <= 1) {
    return n;
  } else {
    return fibonacciRecursive(n - 1) + fibonacciRecursive(n - 2);
  }
}

console.log(fibonacciRecursive(7)); // Output: 13

// ITERATIVE APPROACH
function fibonacciIterative(n) {
  if (n <= 1) {
    return n;
  }

  let fib = 1;
  let prevFib = 1;

  for (let i = 2; i < n; i++) {
    let temp = fib;
    fib += prevFib;
    prevFib = temp;
  }

  return fib;
}

console.log(fibonacciIterative(7)); // Output: 13