Fibonacci algorithm in Javascript

Readme.md

performance

general.js > memonize.js > simple-loop.js

general.js

const num = 20;
const fibonacci = (i) => {
    const sqrt5 = Math.sqrt(5);
    const phi = (sqrt5 + 1) / 2;

    if (i < 2) {
        return i;
    }
    return Math.round(Math.pow(phi, i) / sqrt5);
}

for (let i = 0; i < num; i++) {
    const fib = fibonacci(i);
    console.log(`result fib is ${fib}`);
}

memonize.js

const num = 20;
const fibonacci = () => {
    const memo = [0, 1];
    const fib = (i) => {
        if (i < 0) {
            return undefined;
        }

        if (typeof memo[i] === 'number') {
            return memo[i];
        }

        if (i < 2) {
            memo[i] = i;
        } else {
            memo[i] = fibonacci1(i - 1) + fibonacci1(i - 2);
        }
        return memo[i];
    }

    return fib;
}

for (let i = 0; i < num; i++) {
    const fib = (fibonacci())(i);
    console.log(`result fib is ${fib}`);
}

simple-loop.js

const num = 20;
const fibonacci =  (i) => {
    return (i < 2 ? i : fibonacci1(i -1) + fibonacci1(i - 2))
}

for (let i = 0; i < num; i++) {
    const fib = fibonacci.call(null, i);
    console.log(`result fib is ${fib}`);
}