Run results for: string literal vs array join

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Firefox/91.0

Browser: Firefox 91

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 2 years ago

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; }, '');