Run results for: Direct access vs prototype lookup

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:74.0) Gecko/20100101 Firefox/74.0

Browser: Firefox 74

Operating system: Linux

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
Direct	37834.0 Ops/sec
Semi-proto	36993.2 Ops/sec
Proto	37333.6 Ops/sec

Script Preparation code:

var LD = Array(100).fill(1).map(() => ({ x: 1, y: 2 }))

var P1  = { x: 1 }
var LP1 = Array(100).fill(1).map(() => { var A = Object.create(P1); A.y = 2; return A })

var P2  = { x: 1, y: 2 }
var LP2 = Array(100).fill(1).map(() => Object.create(P2))

Tests:

Direct
var S = 0 for (let x = 0; x < 100; x++) { let next = LD[x] S = (S + next.x + next.y) } console.log(S)
Semi-proto
var S = 0 for (let x = 0; x < 100; x++) { let next = LP1[x] S = (S + next.x + next.y) } console.log(S)
Proto
var S = 0 for (let x = 0; x < 100; x++) { let next = LP2[x] S = (S + next.x + next.y) } console.log(S)

Run results for: Direct access vs prototype lookup

Direct

Semi-proto

Proto