fibonacci counter in typescript

1// declare the array starting with the first 2 values of the fibonacci sequence
2    let fibonacci = [0,1];
3    
4    function listFibonacci(num) {
5    // starting at array index 1, and push current index + previous index to the array
6        for (let i = 1; i < num; i++) {
7            fibonacci.push(fibonacci[i] + fibonacci[i - 1]);
8        }
9        console.log(fibonacci);
10    }
11    
12    listFibonacci(10);
13    

1function isFibonacci(n) {
2  var fib,
3    a = (5 * Math.pow(n, 2) + 4),
4    b = (5 * Math.pow(n, 2) - 4)
5
6  var result = Math.sqrt(a) % 1 == 0,
7    res = Math.sqrt(b) % 1 == 0;
8
9  //fixed this line
10  if (result || res == true) // checks the given input is fibonacci series
11  {
12    fib = Math.round(n * 1.618); // finds the next fibonacci series of given input
13    console.log("The next Fibonacci number is " + fib);
14
15  } else {
16    console.log(`The given number ${n} is not a fibonacci number`);
17  }
18}
19
20$('#fib').on("keyup change", function() {
21  isFibonacci(+this.value)
22})

1'use strict';
2
3let fibonacci: number[] = [0, 1];
4
5function listFibonacci(num: number) {
6  for (let i: number = 2; i < num; i++) {
7    fibonacci[i] = fibonacci[i - 2] + fibonacci[i - 1];
8  }
9  return fibonacci;
10}
11console.log(listFibonacci(10));
12