Run results for: regex replace vs replaceAll vs replace in loop V1.1

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:105.0) Gecko/20100101 Firefox/105.0

Browser: Firefox 105

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
replace	204728.2 Ops/sec
replaceAll	204346.1 Ops/sec
replace in a loop without g flag	6149.1 Ops/sec
replace in a loop, count matches with g flag, replace without g flag	9099.4 Ops/sec

Script Preparation code:

function replaceAll(str, regexp, newValue) {
    let newStr = str;

    while (regexp.test(newStr)) {
        newStr = newStr.replace(regexp, newValue);
    }

    return newStr;
}

function replaceAllCountMatches(str, regexp, newValue) {
    let newStr = str;
    
    for (let i = 0; i < matchesCounter; i++) {
        newStr = newStr.replace(regexp, newValue);
    }

    return newStr;
}

var str = 'Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse molestie consequat, vel illum dolore eu feugiat nulla facilisis a';
var matchesCounter = (str.match(/\s+/g) || []).length;
var result;

Tests:

replace
result = str.replace(/\s+/g, '');
replaceAll
result = str.replaceAll(/\s+/g, '');
replace in a loop without g flag
result = replaceAll(str, /\s+/, '');
replace in a loop, count matches with g flag, replace without g flag
result = replaceAllCountMatches(str, /\s+/, '');

Run results for: regex replace vs replaceAll vs replace in loop V1.1

replace all whitespaces from string. what is faster? replace() with regex with global flag or without global flag and using a loop?

replace

replaceAll

replace in a loop without g flag

replace in a loop, count matches with g flag, replace without g flag