Run results for: Set Array elements vs create new Array

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0

Browser: Firefox 57

Operating system: Windows

Device Platform: Other

Date tested: 6 years ago

Test name	Executions per second
set	14864.9 Ops/sec
recreate	8801.1 Ops/sec

Script Preparation code:

var p = [ ];
for (var i=0; i<5000; i++) {
  p.push([i,i, i,i]);
}

Tests:

set
var p2 = []; for (var i=0, ito=p.length; i<ito; i++) { var px = p[i]; px[0]=i; px[1]=i; p2.push(px); }
recreate
var p2 = []; for (var i=0, ito=p.length; i<ito; i++) { var px = p[i]; p2.push([i,i, px[i], px[i]]); }