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>
Javascript Fibonacci