Simple Javascript script to calculate n-th element of Fibbonaci sequence.
// ? 2017 TheFlyingKeyboard and released under MIT License // theflyingkeyboard.net <html> <body> Enter a number: <input type="text" id="data"> <button onclick="count()">Convert</button> <p>N-th Fibonacci number is equal to</p> <p id="newText"></p> <script> function count(){ var data = document.getElementById("data").value; var n = parseInt(data); n = fibonacci(n); document.getElementById("newText").innerHTML = n; } function fibonacci(n){ var fib = 0; var fibPrev1 = 1; var fibPrev2 = 0; for(var i = 2; i <= n; i++){ fib = fibPrev1 + fibPrev2; fibPrev2 = fibPrev1; fibPrev1 = fib; } return fib; } </script> </body> </html>