Run results for: Direct Array Access vs. New Local Constant Variable in A Loop

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0

Browser: Firefox 78

Operating system: Linux

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
Direct Array Access	145108.3 Ops/sec
Local Variable Access	120927.4 Ops/sec

Script Preparation code:

var arr = [
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
    { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" }, { "key": "value" },
]

var newarr1 = []
var newarr2 = []

Tests:

Direct Array Access
for (var i = 0; i < arr.length; i++) { newarr1.push(arr[i]) }
Local Variable Access
for (var i = 0; i < arr.length; i++) { const el = arr[i] newarr2.push(el) }

Run results for: Direct Array Access vs. New Local Constant Variable in A Loop

Direct Array Access

Local Variable Access