Run results for: String concatenation vs array join

Run details:

User agent: Mozilla/5.0 (Linux; Android 6.0.1; SAMSUNG SM-G900F) AppleWebKit/537.36 (KHTML, like Gecko) SamsungBrowser/13.0 Chrome/83.0.4103.106 Mobile Safari/537.36

Browser: Chrome Mobile 83

Operating system: Android 6.0.1

Device Platform: Mobile

Date tested: 3 years ago

Test name	Executions per second
String concatentation	485.5 Ops/sec
Array join	1187.9 Ops/sec
Array join (w/ push)	24.5 Ops/sec

Script Preparation code:

var str = "";
var i;
var sArr = [];

Tests:

String concatentation
for (i = 1000; i > 0; i--) { str += "String concatenation. "; }
Array join
for (i = 1000; i > 0; i--) { sArr[i] = "String concatenation. "; } str = sArr.join("");
Array join (w/ push)
for (i = 1000; i > 0; i--) { sArr.push("String concatenation. "); } str = sArr.join("");

Run results for: String concatenation vs array join

String concatentation

Array join

Array join (w/ push)