var var1 = 0;
var var2 = 1;
var var3;
var num = 20;
document.write(var1 + "<br />");
document.write(var2 + "<br />");
for (var i = 3; i <= num; i++) {
var3 = var1 + var2;
var1 = var2;
var2 = var3;
document.write(var3 + "<br />");
}
var var1 = 0;
var var2 = 1;
var var3;
var num = 20;
document.write(var1 + "<br />");
document.write(var2 + "<br />");
for (var i = 3; i <= num; i++) {
var3 = var1 + var2;
var1 = var2;
var2 = var3;
document.write(var3 + "<br />");
}Best, I'm doing a Fibonacci Series, but I want to see a message with prompt es up, so you can fill in a number, then the returns with the Fibonacci Series. Who would be able to help me? Above I have now.
Share Improve this question edited May 10, 2020 at 15:41 Penny Liu 17.6k5 gold badges86 silver badges108 bronze badges asked Apr 7, 2014 at 10:16 GigiGigi 91 gold badge1 silver badge2 bronze badges 3- 1 stackoverflow./questions/7944239/… – Dhaval Marthak Commented Apr 7, 2014 at 10:18
- What number should the user fill in? And what should be returned, do you have some examples of input/output? – David Thomas Commented Apr 7, 2014 at 10:18
- Does this answer your question? Generating Fibonacci Sequence – Matej J Commented Jun 23, 2020 at 7:06
10 Answers
Reset to default 3I have created demo, hope it will help you.
var i;
var fib = [0, 1];
var limit = window.prompt('Enter the limit for your series:', '');
for (i = 2; i < parseInt(limit); i++) {
fib[i] = fib[i - 2] + fib[i - 1];
}
console.log(fib);
Demo Link
function myFunction() {
var n = document.getElementById("myNumber").value;
document.getElementById("demo").innerHTML = fibonacciGenerator (n);
}
var sequence = [0]; // sequence = []; if you want sequence [1] = 1;
var previousNumber = 1;
var presentNumber = 0;
var sum = 0;
function fibonacciGenerator (n) {
while (sequence.length < n) {
sum = previousNumber + presentNumber;
previousNumber = presentNumber;
presentNumber = sum;
sequence.push(sum);
}
return (sequence);
}<!DOCTYPE html>
<html>
<body>
<h1>Fibonacci Generator </h1>
<input type="number" id="myNumber" value="0">
<p>Enter a number to generate Fibonacci array.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
</body>
</html>Using ES6 generator
function* fiboGen(len, current = 0, next = 1) {
if (len === 0) {
return current;
}
yield current;
yield* fiboGen(len - 1, next, current + next);
}
const fibo = [...fiboGen(10)];
console.log(fibo);
//[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
you need to use a prompt box to get the number:
window.prompt("sometext","defaultText");
http://www.w3schools./js/js_popup.asp
I hope that this is what you are looking for.
HTML:
Which sequence of the Fibonacci pattern do you want to find?
<br><br>
<input type="text" id="inputtext">
<br><br>
<input type="button" value="Find out" id="btn">
<br><br>
<b id="ID"></b>
JS:
function add(a, b) {
while (a.length < b.length) a.unshift(0);
while (a.length > b.length) b.unshift(0);
var carry = 0,
sum = [];
for (var i = a.length - 1; i >= 0; i--) {
var s = a[i] + b[i] + carry;
if (s >= 10) {
s = s - 10;
carry = 1;
} else {
carry = 0;
}
sum.unshift(s);
}
if (carry) sum.unshift(carry);
return sum;
}
function fib(n) {
var f1 = [0];
var f2 = [1];
while (n--) {
var f3 = add(f1, f2);
f1 = f2;
f2 = f3;
}
return f1.join("");
}
document.getElementById("btn").onclick = function () {
var inputnum = parseFloat(document.getElementById("inputtext").value);
document.getElementById("ID").innerHTML = fib(inputnum).toString();
};
Fiddle.
var number = prompt("Enter number ");
....... your code ....
You can do the following:
var var1 = 0;
var var2 = 1;
var var3;
var num = window.prompt("Enter the limit for your series:","");
//var num = 20;
var str = '';
str+=var1+','+var2;
for(var i=3; i <= parseInt(num);i++)
{
var3 = var1 + var2;
var1 = var2;
var2 = var3;
str+=','+var3;
}
document.write(str);
<!doctype html>
<html lang="en">
<head>
<body>
<script type="text/javascript">
var f1=0,f2=1,f3;
var i;
alert("enter a text"+n);
var n=prompt("enter the number");
document.write("the fibonacci series is "+"<br/>");
for(i=2;i<=n;i++)
{
f3=f1+f2;
f1=f2;
f2=f3;
document.write(f3+"<br/>");
}
</script>
<style>
body {background-color:#66ff66}
</style>
</head>
</body>
i came up with this solution to get the n index Fibonacci value. you can use the findFac0(); to pass the index you need to get the Fibonacci value.
function findFac(n){
if (n===1)
{
return [0, 1];
}
else
{
var s = findFac(n - 1);
s.push(s[s.length - 1] + s[s.length - 2]);
return s;
}
}
function findFac0(n){
var vv1 = findFac(n);
return vv1[n-1];
}
console.log(findFac0(10));
I've tried this: it might work:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Fibonacci</title>
<style>
* {
outline: 0px;
margin: 0px;
}
input[type="number"] {
color: blue;
border: 2px solid black;
width: 99.58vw;
}
</style>
</head>
<body>
<div id="myDiv" style="color: white;background-color: blue;">Numbers Here</div>
<input type="number" id="input1" oninput="fibonacciProgram(this.value)" placeholder="Type Some Numbers Here">
<script>
function fibonacciProgram(numberCount) {
let resultElement = document.getElementById("myDiv");
resultElement.innerHTML = " ";
if (isNaN(numberCount) || numberCount <= 0) {
resultElement.innerHTML = "please enter a number";
return;
}
let firstBox = 0;
let secondBox = 1;
let swichBox;
let entries = [];
entries.push(secondBox);
while (numberCount > 1) {
swichBox = firstBox + secondBox;
entries.push(swichBox);
firstBox = secondBox;
secondBox = swichBox;
numberCount--;
}
resultElement.innerHTML = entries.join(', ');
}
</script>
</body>
</html>