Why profit is "1"?

Question

JavaScript

Why is profit equal to "1"? After all, reduce inside itself does not return anything.

const [firstKey,  ...keys] = 'totalPrice'.split('.');

const profit = keys.reduce((val, key) => {
}, { items: [], totalPrice: 1 }[firstKey]);

console.log(profit)

Answer 1

Step through your code and you will immediately see that keys is an empty array
And reduce on an empty array simply returns init value without even going to the callback