Run results for: Regex vs split/join - actual replace

Now regex flies and split crawls. BTW that regex match split plus join is what jQuery's removeClass() does - just much worse. Had to double check just in case that there's some hidden trick involved.

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.77 Safari/537.36

Browser: Chrome 91

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Regex	1280864.5 Ops/sec
Regex match as Split - jQuery style :-)	385368.3 Ops/sec
Split and Join	337364.6 Ops/sec

Script Preparation code:

var sep = "[\x20\t\r\n\f]";
var not_sep = "[^\x20\t\r\n\f]";

var str = 'Abcd efghij klmnopqrstuv wxy Abcd efghij klmnopqrstuv wxy Abcd efghij klmnopqrstuv wxyAbcd efghij klmnopqrstuv wxy Abcd efghij klmnopqrstuv wxy Abcd efghij klmnopqrstuv wxy';

Tests:

Regex
var name = "skin-oasis|background-dynamic"; let re = new RegExp(name + "(?:" + sep + "+|$)"); var res = str.replace(re, "");
Regex match as Split - jQuery style :-)
let re = new RegExp(not_sep + "+", 'g'); let arr = str.match(re); for (i = 0; i < arr.length; ++i) { if ( arr[i] == "skin-oasis" ) arr[i] = null; } arr.join(" ");
Split and Join
let re = new RegExp(name + "(?:" + sep + "|$)"); let arr = str.split(re); for (i = 0; i < arr.length; ++i) { if ( arr[i] == "skin-oasis" ) arr[i] = null; } arr.join(" ");

Run results for: Regex vs split/join - actual replace

Now regex flies and split crawls. BTW that regex match split plus join is what jQuery's removeClass() does - just much worse. Had to double check just in case that there's some hidden trick involved.

Regex

Regex match as Split - jQuery style :-)

Split and Join