Run results for: Regex vs split/join

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:65.0) Gecko/20100101 Firefox/65.0

Browser: Firefox 65

Operating system: Mac OS X 10.14

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
Regex	56722.0 Ops/sec
Split and Join	332887392.0 Ops/sec

Script Preparation code:

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
str.replace(/./g, "$&Z");
Split and Join
str.split('').join('Z') + 'Z';

Run results for: Regex vs split/join

Regex

Split and Join