Run results for: String concatenation vs array join

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 14_8_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.1.2 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 14

Operating system: iOS 14.8.1

Device Platform: Mobile

Date tested: 2 years ago

Test name	Executions per second
String concatentation	6948.5 Ops/sec
Array join	6516.9 Ops/sec
Array join (w/ push)	29.8 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)