function fib(n) {  
    if (n <= 1) {
        return n
    }

    let [a, b] = [0, 1]
    
    for (let k = 0; k < n-1; k++) {
        ;[a, b] = [b, a + b]
    }
    
    return b
}

fibs10 = Array(10).fill().map((_, i) => fib(i))
console.log(fibs10)