Run results for: Object.create([array])

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.72 Safari/537.36 Edg/90.0.818.42

Browser: Chrome 90

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Read: base	2581054.2 Ops/sec
Read: stagedEmpty	1197784.6 Ops/sec
Read: stagedFilled	2342795.0 Ops/sec

Script Preparation code:

var base = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20];
var stagedEmpty = Object.create(base);
var stagedFilled = Object.create(base);
stagedFilled[1] = 101;
stagedFilled[2] = 102;
stagedFilled[10] = 110;
stagedFilled[12] = 112;
stagedFilled[15] = 115;

Tests:

Read: base
base[1] + base[2] + base[10] + base[12] + base[15]
Read: stagedEmpty
stagedEmpty[1] + stagedEmpty[2] + stagedEmpty[10] + stagedEmpty[12] + stagedEmpty[15]
Read: stagedFilled
stagedFilled[1] + stagedFilled[2] + stagedFilled[10] + stagedFilled[12] + stagedFilled[15]

Run results for: Object.create([array])

Read: base

Read: stagedEmpty

Read: stagedFilled