Run results for: Can JavaScript benefit from the ECS pattern 2? With split components position and health 5

JS arrays are weird and (probably?) not memory-contiguous, but just for kicks, let's see what difference there is (if any) between performing the same action on 1,000,000 objects in an object-oriented style (with the method attached to the object) vs an ECS-style (with the behavior separated from the raw data)

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 26_0_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) FxiOS/143.2 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 26

Operating system: iOS 26.0.1

Device Platform: Mobile

Date tested: 9 months ago

ECS-style

212/s

OO-style

114/s

View exact numbers

Test name	Executions per second
✓ ECS-style	212 Ops/sec
OO-style	114 Ops/sec

Script Preparation code:

class Point {
    constructor(x, y) {
        this.x = x;
        this.y = y;
        this.health = 100;
    }

    updatePosition() {
        this.x += 2;
        this.y += 2;
    }

    takeDamage() {
        this.health -= 1;
    }
}

var pointClasses = [];

var pointCompList = [];
var healthCompList = [];

const entityCount = 1000000;

for (let i = 0; i < entityCount; i++) {
    pointClasses.push(new Point(0, 0));
    pointCompList.push({
        x: 0,
        y: 0
    });
    healthCompList.push(100);
}

Tests:

OO-style
for (let i = 0; i < entityCount; i++) { const pointClass = pointClasses[i]; pointClass.takeDamage(); pointClass.takeDamage(); }; for (let i = 0; i < entityCount; i++) { const pointClass = pointClasses[i]; pointClass.updatePosition(); pointClass.updatePosition(); };
ECS-style
function updatePosition(i) { const pointComp = pointCompList[i]; pointComp.x += 2; pointComp.y += 2; } function takeDamage(i) { healthCompList[i] -= 1; } for (let i = 0; i < entityCount; i++) { updatePosition(i); updatePosition(i); } for (let i = 0; i < entityCount; i++) { takeDamage(i); takeDamage(i); }