Should product() return 0 for an empty array?

[stevensacks]

https://github.com/1-liners/1-liners/tree/master/documentation#product

Currently, it returns 1. Shouldn't an empty array product be 0 not 1? After all, nothing from nothing leaves nothing. 0 * 0 = 0.

It's easy to fix with a ternary check for length.

export default (array) => array.length ? array.reduce((a, b) => (a * b), 1) : 0;

https://www.youtube.com/watch?v=aj5DccgBYeM 😉

[tomek-he-him]

While 0 is the “nothing” value for addition (anything + 0 == anything), I really feel 1 is the “nothing” value for multiplication (anything × 1 == anything). I’m sure there’s some academic papers backing up my feelings. 😄

[stoeffel]

jop, 1 is the identity property for multiplication.

[stevensacks]

Not sure what "jop" means. I was unaware that 1 is the identity property for multiplication. #TIL

[stoeffel]

jop = yes 😸