Eloquent Javascript, listToArray. Why does my for loop return rest [object] when input array has more than 3 elements -

i'm working through eloquent javascript chapter 4. exercise asks

write function arraytolist builds data structure previous 1 when given [1, 2, 3] argument

using code below can necessary output - when number of elements in array 3 or less.

function createnode (value, rest) {   return {     value: value,   rest: rest } };   function arraytolist(arr) {   var index = arr.length;   firstnode = createnode(index,null);   listbuild = firstnode;  (i =(index-1); >0; i--) {   listbuild = createnode(i,listbuild) } 

question arraytolist([1,2,3]) produces desired result of "{ value: 1, rest: { value: 2, rest: { value: 3, rest: null } } }"

arraytolist([1,2,3,4]) produces output of "{ value: 1, rest: { value: 2, rest: { value: 3, rest: [object] } } }"

why function generate rest property of [object] in case?

thanks!

your function seems work fine, suspect output issue, not problem code.

if you're using node.js test code, you've run gotcha implementation of console.log. in node.js, console.log formats objects using util.inspect, , default util.inspect display nested objects depth of 2. can change calling util.inspect directly , using depth option. set higher number, or can set null unlimited depth:

var util = require('util'); var result = arraytolist([1,2,3,4]); console.log(util.inspect(result, { depth: null }));