Run results for: Format number | Regex vs Code V1.1

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:103.0) Gecko/20100101 Firefox/103.0

Browser: Firefox 103

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
regex test	429465.2 Ops/sec
code test	261566.1 Ops/sec

Script Preparation code:

var char = ' '
var count = 3

function formatNumber(num) {
    const arr = num.toString().split('');
    let it = 1;

    for (let i = arr.length - 1; i >= 1; i--) {
        if (it % count === 0) {
            arr.splice(i, 0, char);
        }
        it++;
    }
    return arr.join('');
}

function formatNumber1bis(num) {
    const arr = `${num}`.split('');
    let it = 1;

    for (let i = arr.length - 1; i >= 1; i--) {
        if (it % count === 0) {
            arr.splice(i, 0, char);
        }
        it++;
    }
    return arr.join('');
}

function formatNumber2(num) {
    return num.toString().replace(/\B(?=(\d{3})+(?!\d))/g, char);
}

function formatNumber2bis(num) {
    return `${num}`.replace(/\B(?=(\d{3})+(?!\d))/g, char);
}

Tests:

regex test (toString)
const numbers = [1, 100, 1000, 10000, 100000, 1000000, 10000000, 1000000000] for (let i = 0; i < numbers.length; i++) { formatNumber2(numbers[i]) }
code test (toString)
const numbers = [1, 100, 1000, 10000, 100000, 1000000, 10000000, 1000000000] for (let i = 0; i < numbers.length; i++) { formatNumber(numbers[i]) }
regex test ````
const numbers = [1, 100, 1000, 10000, 100000, 1000000, 10000000, 1000000000] for (let i = 0; i < numbers.length; i++) { formatNumber2bis(numbers[i]) }
code test ````
const numbers = [1, 100, 1000, 10000, 100000, 1000000, 10000000, 1000000000] for (let i = 0; i < numbers.length; i++) { formatNumber1bis(numbers[i]) }

Run results for: Format number | Regex vs Code V1.1

Regex VS Code for number format

regex test (toString)

code test (toString)

regex test ````

code test ````