Proper use of ||

Question

The general question I suppose is: when does || return the item on the left, and when does it return the item on the right?

The specific question, is why doesn\'t t

Answer 1

Your code doesn't work because you can't use the value in cache when it's 0 as 0 || func() asks for the function to be called.

So it always call the second term for 0 and thus makes a stack overflow as the recursion has no end.

A solution would be to change your internal function like this :

function fibnonacci(number) {
    if (number in cache) return cache[number];
    return cache[number] = fibnonacci(number - 1) + fibonacci(number - 2);
}

As an aside please note the spelling of Fibonacci.