Run results for: JS: String '+' v.s. join

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/109.0

Browser: Firefox 109

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
+	83439.3 Ops/sec
join	48078.3 Ops/sec

Script Preparation code:

var initialStr = "aAbBcCdDeEfFgGhHiIjJkKlLmMnNoOpPqQrRsStTuUvVwWxXyYzZ";
var initialSuffix = 123456789;
var nLoops = 100;

Tests:

+
var str = ''; var suffix = initialSuffix; for (var i = 0; i < nLoops; i++, suffix *= 100) { str += initialStr + suffix; }
join
var stringArray = []; var suffix = initialSuffix; for (var i = 0; i < nLoops; i++, suffix *= 100) { stringArray.push(initialStr + suffix); } stringArray.join('');