Run results for: String concatenation vs array join vs array reduce

Run details:

User agent: Mozilla/5.0 (Linux; Android 11; Pixel 2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Mobile Safari/537.36

Browser: Chrome Mobile 92

Operating system: Android

Device Platform: Mobile

Date tested: 3 years ago

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("");
Array reduce
for (i = 1000; i > 0; i--) { sArr[i] = "String concatenation. "; } str = sArr.reduce((a, v) => a += `${v} `, '');
Array reduce trim
for (i = 1000; i > 0; i--) { sArr[i] = "String concatenation. "; } str = sArr.reduce((a, v) => a += `${v} `, '').trim();