Run results for: 2D array copy - slice vs spread operator vs loop

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser: Chrome 128

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Array.prototype.slice	89418.8 Ops/sec
spread operator	75147.5 Ops/sec
simple loop	46007.3 Ops/sec
placement loop	46858.7 Ops/sec
pre-built array loop	45792.8 Ops/sec
optimizing slice	91354.2 Ops/sec
optimizing spread operator	74597.4 Ops/sec

Tests:

Array.prototype.slice
let param = new Array(50); for (let a = 0; a < 50; a++) { param[a] = new Array(50); for (let b = 0; b < 50; b++) { param[a][b] = b; } } let ans = []; for (let i = 0; i < param.length; i++) { ans.push(param[i].slice()); }
spread operator
let param = new Array(50); for (let a = 0; a < 50; a++) { param[a] = new Array(50); for (let b = 0; b < 50; b++) { param[a][b] = b; } } let ans = []; for (let i = 0; i < 50; i++) { ans.push([...param[i]]); }
simple loop
let param = new Array(50); for (let a = 0; a < 50; a++) { param[a] = new Array(50); for (let b = 0; b < 50; b++) { param[a][b] = b; } } let ans = []; for (let i = 0; i < 50; i++) { ans.push([]); for(let j = 0; j < 50; j++) { ans[i].push(param[i][j]); } }
placement loop
let param = new Array(50); for (let a = 0; a < 50; a++) { param[a] = new Array(50); for (let b = 0; b < 50; b++) { param[a][b] = b; } } let ans = []; for (let i = 0; i < 50; i++) { ans.push([]); for(let j = 0; j < 50; j++) { ans[i][j] = param[i][j]; } }
pre-built array loop
let param = new Array(50); for (let a = 0; a < 50; a++) { param[a] = new Array(50); for (let b = 0; b < 50; b++) { param[a][b] = b; } } let ans = new Array(50); for (let i = 0; i < 50; i++) { ans[i] = new Array(50); for(let j = 0; j < 50; j++) { ans[i][j] = param[i][j]; } }
optimizing slice
let param = new Array(50); for (let a = 0; a < 50; a++) { param[a] = new Array(50); for (let b = 0; b < 50; b++) { param[a][b] = b; } } let ans = new Array(50); for (let i = 0; i < param.length; i++) { ans[i] = param[i].slice(); }
optimizing spread operator
let param = new Array(50); for (let a = 0; a < 50; a++) { param[a] = new Array(50); for (let b = 0; b < 50; b++) { param[a][b] = b; } } let ans = new Array(50); for (let i = 0; i < param.length; i++) { ans[i] = [...param[i]]; }

Run results for: 2D array copy - slice vs spread operator vs loop

Compare 2D array copy with the spread operator vs slice vs loop

Array.prototype.slice

spread operator

simple loop

placement loop

pre-built array loop

optimizing slice

optimizing spread operator