Run results for: 'concat()' vs '+' vs '+=' for strings

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.79 Safari/537.36

Browser: Chrome 67

Operating system: Mac OS X 10.13.5

Device Platform: Desktop

Date tested: 5 years ago

Script Preparation code:

var somestr = "hai!";
var result = "";

Tests:

concat()
for(i = 0; i < 1000; i++) { result = result.concat(somestr); }
plus_operator
for(i = 0; i < 1000; i++) { result = result + somestr; }
plus_eq_operator
for(i = 0; i < 1000; i++) { result += somestr; }
Array.join
var a = []; for(i = 0; i < 1000; i++) { a.push(somestr); } result = a.join('');