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

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36

Browser: Chrome 90

Operating system: Windows

Device Platform: Desktop

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();