Run results for: Regex collapse vs for loop

Run details:

User agent: Mozilla/5.0 (Linux; Android 9; Redmi Note 8) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/93.0.4577.82 Mobile Safari/537.36

Browser: Chrome Mobile 93

Operating system: Android

Device Platform: Mobile

Date tested: 2 years ago

Test name	Executions per second
Regex inplace replace	15453.6 Ops/sec
for loop	16333.9 Ops/sec

Script Preparation code:

var string = "aaaaabaaaaa";
var string1 = "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum."

Tests:

Regex inplace replace
string.replace(/(?:(\w)(?:\1)*)/g, "$1") string1.replace(/(?:(\w)(?:\1)*)/g, "$1")
for loop
const collapse = (string) => { let final = "", prev = ""; for (let i = 0, len = string.length, char; i < len; i++) { if ((char = string[i]) !== prev) { final += (prev = char); } } return final; }; collapse(string); collapse(string1);

Run results for: Regex collapse vs for loop

Collapse function removes adjacent duplicates in the string

Regex inplace replace

for loop