Run results for: Filter Cards

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:98.0) Gecko/20100101 Firefox/98.0

Browser: Firefox 98

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Match via loop	709952.0 Ops/sec
Match via regex	2177292.0 Ops/sec

Script Preparation code:

const cardMin = 12
const cardMax = 19
const cardSeparators = ['.', '_', '-', ' ']

window.filterCardsViaLoop = (str) => {
    if (str.length < cardMin) {
        return []
    }
    let nl = 0
    let ns = -1
    let i = 0
    const ni = []
    while (i < str.length) {
        if ((str.length - i) + nl < cardMin) {
            return ni
        }
        const c = str[i]
        const cc = c.charCodeAt(0)
        const isN = cc >= 48 && cc <= 57
        const isS = cardSeparators.includes(c)
        if (isN) {
            if (nl === 0) {
                ns = i
            }
            nl += 1
        } else if (!isS) {
            if (nl >= cardMin && nl <= cardMax) {
                ni.push([ns, i - 1])
            }
            nl = 0
        }
        i += 1
    }
    if (nl >= cardMin && nl <= cardMax) {
        ni.push([ns, i])
    }
    return ni
}

const regex = /[0-9 ]{12,19}/g
window.filterCardsViaRegex = (str) => {
    const ni = []
    while (true) {
        const matches = regex.exec(str)
        if (!matches) {
            break;
        }
        const lastIndex = regex.lastIndex
        ni.push([lastIndex, lastIndex + matches[0].length])
        i += 1
    }
    return ni
}

Tests:

Match via loop
filterCardsViaLoop('this string has a pan here => 411111111111 <=')
Match via regex
filterCardsViaRegex('this string has a pan here => 411111111111 <=')

Run results for: Filter Cards

Compares filtering card PANs by regex vs a for loop

Match via loop

Match via regex