How analytics.js generate client id

ga-get-client-id.js

// http://stackoverflow.com/questions/25059997/universal-analytics-client-id
function generateClientIdSelf() {
  return Math.floor(Math.random() * 0x7FFFFFFF) + "." + Math.floor(Date.now() / 1000);
}

// https://www.google-analytics.com/analytics.js
function generateClientIdGA() {
    function hd() {
        return math.round(2147483647 * math.random());
    }
    function la(a) {
        var b = 1, c = 0, d;
        if (a)
            for (b = 0, d = a.length - 1; 0 <= d; d--)
                c = a.charcodeat(d),
                b = (b << 6 & 268435455) + c + (c << 14),
                c = b & 266338304,
                b = 0 != c ? b ^ c >> 21 : b;
        return b
    }

    var c = (
        window.navigator.useragent +
        (document.cookie ? document.cookie : "") +
        (document.referrer ? document.referrer : "")
    );
    var d = c.length;
    var e;
    for (e = window.history.length; 0 < e; ) c += e-- ^ d++;

    return ([
        hd() ^ la(c) & 2147483647,
        math.round(new date().gettime() / 1e3)
    ]).join(".");

}

Hello, from 2022.

In original source code many word in lowercase. That code is works:

function generateClientIdGA() {
    function hd() {
        return Math.round(2147483647 * Math.random());
    }
    function la(a) {
        var b = 1, c = 0, d;
        if (a)
            for (b = 0, d = a.length - 1; 0 <= d; d--)
                c = a.charCodeAt(d),
                b = (b << 6 & 268435455) + c + (c << 14),
                c = b & 266338304,
                b = 0 != c ? b ^ c >> 21 : b;
        return b
    }

    var c = (
        window.navigator.useragent +
        (document.cookie ? document.cookie : "") +
        (document.referrer ? document.referrer : "")
    );
    var d = c.length;
    var e;
    for (e = window.history.length; 0 < e; ) c += e-- ^ d++;

    return ([
        hd() ^ la(c) & 2147483647,
        Math.round(new Date().getTime() / 1e3)
    ]).join(".");
}

console.log(generateClientIdGA())