Run results for: Fastest way to list children: childNodes vs children vs firstChild/nextSibling vs firstElementChild/nextElementSibling v2

Result: firstElementChild is the fastest yielding 3-4X performance. With lastElementChild close 2nd. Other observations: doing for loop i-- with children shows ~150% higher performance vs i++. And unloading it into a variable prior yields another ~200% boost

Go to the benchmark

Test name	Executions per second
✓ firstElementChild nextElementChild	48,043,380 Ops/sec
lastElementChild previousElementChild	45,576,992 Ops/sec
firstChild nextSibling	22,137,484 Ops/sec
children-- (into variable)	11,370,601 Ops/sec
children-- (direct)	8,896,792 Ops/sec
ChildNodes for-- (direct)	6,044,884 Ops/sec
children (direct)	5,613,930 Ops/sec
ChildNodes for-- (into variable)	5,037,688 Ops/sec
ChildNodes for (into variable)	4,171,763 Ops/sec
childNodes foreach	3,375,417 Ops/sec

Test name

Executions per second

✓ firstElementChild nextElementChild

48,043,380 Ops/sec

lastElementChild previousElementChild

45,576,992 Ops/sec

firstChild nextSibling

22,137,484 Ops/sec

children-- (into variable)

11,370,601 Ops/sec

children-- (direct)

8,896,792 Ops/sec

ChildNodes for-- (direct)

6,044,884 Ops/sec

children (direct)

5,613,930 Ops/sec

ChildNodes for-- (into variable)

5,037,688 Ops/sec

ChildNodes for (into variable)

4,171,763 Ops/sec

childNodes foreach

3,375,417 Ops/sec

Tests:

childNodes foreach
parent.childNodes.forEach(function (node) { let n = node; });
children (direct)
for (let i = 0; i < parent.children.length; i++) { let n = parent.children[i]; }
firstChild nextSibling
let elem = parent.firstChild; do { let n = elem; } while (elem = elem.nextSibling)
firstElementChild nextElementChild
let elem = parent.firstElementChild; do { let n = elem; } while (elem = elem.nextElementSibling)
ChildNodes for (into variable)
let children = parent.childNodes; for (let i = 0; i < children.length; i++) { let n = children[i]; }
children-- (direct)
for (let i = parent.children.length-1; i >= 0; i--) { let n = parent.children[i]; }
ChildNodes for-- (into variable)
for (let i = parent.childNodes.length-1; i >= 0; i--) { let n = parent.childNodes[i]; }
ChildNodes for-- (direct)
let children = parent.childNodes; for (let i = children.length-1; i >= 0; i--) { let n = children[i]; }
lastElementChild previousElementChild
let elem = parent.lastElementChild; do { let n = elem; } while (elem = elem.previousElementSibling)
children-- (into variable)
let children = parent.children for (let i = children.length-1; i >= 0; i--) { let n = children[i]; }