fibonacci-generator-function.js

function* fibonacci() {
    let prev = 0;
    let next = 1;

    yield prev;
    yield next;

    // Add previous and next and yield them forever
    while (true) {
        const newValue = next + prev;
        yield newValue;
        prev = next;
        next = newValue;
    }
}

const fib = fibonacci();

for (let i = 0; i < 10; i++) {
    const fibValue = fib.next().value;
    console.log(fibValue);
}