Run results for: 2dArray[a][b] vs getValue(obj, a, b);

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.229 Whale/2.10.123.42 Safari/537.36

Browser: Chrome 90

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Normal access	2431450.8 Ops/sec
Conditional index-swapped access	1713081.9 Ops/sec

Script Preparation code:

arr = new Array(100).fill(null).map((_, i) => new Array(100).fill(null).map((_, j) => i + "," + j));

objA = {};
objB = {};
objs = [objA, objB];

randomValues = new Array(10000).fill(null).map(() => [Math.floor(Math.random()*100), Math.floor(Math.random()*100), objs[Math.floor(Math.random()*2)]]);

function getValue(obj, a , b) {
  if(obj === objA)
    return arr[a][b];
  else
    return arr[b][a];
}

Tests:

Normal access
const [a, b] = randomValues[Math.floor(Math.random()*10000)]; arr[a][b];
Conditional index-swapped access
const [a, b, obj] = randomValues[Math.floor(Math.random()*10000)]; getValue(obj, a, b);

Run results for: 2dArray[a][b] vs getValue(obj, a, b);

Conditional 2D Array index-swapped get performance test.

Normal access

Conditional index-swapped access