Find separation values from a starting node

Question

I found on some online coding exercises and this one looks really cool and I wanted to give it a shot.

Problem Statement

Quinn is a pretty popul

Answer 1

My attempt to understand

var persons = input.split(/\s+/).slice(1).reduce(function(obj,name,i,names){
    return (obj[name] = (obj[name] || []).concat([names[i%2 ? i-1 : i+1]]), obj);

},{});

First input.split(/\s+/).slice(1) Gives us an array with all of the names in it. Now

(obj[name] = (obj[name] || []).concat([names[i%2 ? i-1 : i+1]]), obj);

obj is set by default to due to {} according to the reduce method property.

name is current value which is basically going from Alden all the way to Ally. i will go from 1-10 and names is the array

Now we are saying set obj[name] = obj[name].concat([names[i%2 ? i-1 : i+1]]),obj); IF this is possible. If this isn't possible set obj[name] = [].concat([names[i%2 ? i-1 : i+1]]),obj);. This is my interpretation from reading up on ||

Example iteration

first obj = {}, and name will be Alden so the type Alden i.e persons = { Alden: ..} will be obj[Alden].concat(names[2],obj), it will be 2, since 1 mod 2 doesn't get reached.

Now there is where I am a bit confused... what exactly is the ,obj doing here..? am I interpreting this right?