how to do fibonacci sequence in javascript code example

Example 1: how to generate a fibonacci sequence in javascript

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

Example 2: javascript fibonacci

function fibonacci(n) {
   return n < 1 ? 0
        : n <= 2 ? 1
        : fibonacci(n - 1) + fibonacci(n - 2);
}

console.log(fibonacci(4));