Run results for: String concatenation vs array join

Run details:

User agent: Mozilla/5.0 (Linux; Android 10; Mi MIX 2S) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.127 Mobile Safari/537.36 OPR/69.3.3606.65458

Browser: Opera Mobile 69

Operating system: Android

Device Platform: Mobile

Date tested: one year ago

Test name	Executions per second
String concatentation	1297.8 Ops/sec
Array join	3191.1 Ops/sec
Array join (w/ push)	43.9 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)