Run results for: Caching values in Array vs. Caching values in Object

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36 Edg/112.0.1722.64

Browser: Chrome 112

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Object Saving	803.5 Ops/sec
Array Saving	782.7 Ops/sec
Prefilled Array Saving	1120347.0 Ops/sec
Preinitialized Array Saving	166.3 Ops/sec
PreinitializedArray V2	217.6 Ops/sec

Script Preparation code:

var objectArray = new Array(10000).fill(null);
var arrayArray = new Array(10000).fill(null);
var prefilledArray = Array.from(new Array(3), () => new Array(3))
var preinitializedArray = new Array(10000);

Tests:

Object Saving
const a = 100; const b = "string"; const c = { a: 1000, b: "objectString"} for(const [index, ] of objectArray.entries()) { objectArray[index] = { a, b, c }; }
Array Saving
const a = 100; const b = "string"; const c = { a: 1000, b: "objectString"} for(const [index, ] of arrayArray.entries()) { arrayArray[index] = [ a, b, c ]; }
Prefilled Array Saving
const a = 100; const b = "string"; const c = { a: 1000, b: "objectString"} for(const [index, ] of prefilledArray.entries()) { prefilledArray[index][0] = a; prefilledArray[index][1] = b; prefilledArray[index][2] = c; }
Preinitialized Array Saving
const a = 100; const b = "string"; const c = { a: 1000, b: "objectString"} preinitializedArray = Array.from(preinitializedArray, () => new Array(3)); for(const [index, ] of preinitializedArray.entries()) { preinitializedArray[index][0] = a; preinitializedArray[index][1] = b; preinitializedArray[index][2] = c; }
PreinitializedArray V2
const a = 100; const b = "string"; const c = { a: 1000, b: "objectString"} preinitializedArray = Array.from(preinitializedArray, () => [ , , ]); for(const [index, ] of preinitializedArray.entries()) { preinitializedArray[index][0] = a; preinitializedArray[index][1] = b; preinitializedArray[index][2] = c; }

Run results for: Caching values in Array vs. Caching values in Object

Object Saving

Array Saving

Prefilled Array Saving

Preinitialized Array Saving

PreinitializedArray V2