It is not sarcasm. Yes, they love working with me, they learn new things from me and they use it. Generally their face is like "o_O I wish I've learned it befor

It is not sarcasm. Yes, they love working with me, they learn new things from me and they use it. Generally their face is like "o_O I wish I've learned it before". I use build-in functions of PHP and Java in way without loops, there is nothing unknown. I don't write Erlang code. Here is an example what I mean; <?php declare(strict_types=1); function fibonacci_nth(int $n): int { if($n === 0) return 0; if($n === 1) return 1; else return fibonacci_nth($n - 2) + fibonacci_nth($n - 1); } function fibonacci_series(int $n): array { return array_map('fibonacci_nth', range(0, $n)); } And here in Python class Fibonacci: def fibonacci_nth(self, n): if(n == 0): return 0 if(n == 1): return 1 else: return self.fibonacci_nth(n-1) + self.fibonacci_nth(n-2) def fibonacci_series(self, n): return [self.fibonacci_nth(x) for x in range(n+1)]