Run results for: array vs object access

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.129 Safari/537.36

Browser: Chrome 81

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
test object accessor	47772.0 Ops/sec
test array indexer	1118595.6 Ops/sec
test object accessor + gets after	41137.8 Ops/sec
test array indexer + gets after	872883.1 Ops/sec

Script Preparation code:

var arr = new Array(1000).fill(0);

Tests:

test object accessor
for(const key in arr);
test array indexer
for(const idx of arr);
test object accessor + gets after
for(const key in arr); let i = 1000; while(arr[--i]);
test array indexer + gets after
for(const idx of arr); let i = 1000; while(arr[--i]);