Run results for: string literal vs array join

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.192 Safari/537.36

Browser: Chrome 88

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
array.join	3930958.0 Ops/sec
string literal	15013380.0 Ops/sec

Script Preparation code:

var arr = Array(50000)
  .fill(1)
  .map(() => 'A' + Math.ceil(Math.random() * 100));

Tests:

array.join
var res=arr.join('; ');
string literal
var finalString2 = arr.reduce((res, item) => { return `${res}; ${item}`; }, '');
string concatenation
var finalString3 = arr.reduce((res, item) => { return res + '; ' + item; }, '');