Run results for: getCookie variations

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36

Browser: Chrome 129

Operating system: Windows

Device Platform: Desktop

Date tested: 2 months ago

Test name	Executions per second
original	1037942.4 Ops/sec
Regex	1033483.2 Ops/sec
regexloop	599126.9 Ops/sec
lastIndexOf	2133976.0 Ops/sec

Script Preparation code:

function getCookieIX(name,str){
  name = name+'=';
  var ck = str || document.cookie;
  var idx = ck.lastIndexOf(name);
  if(idx==-1){ return undefined}
  var nameLength = name.length;
  var p1 = ck.substring(idx+nameLength);
  var idx2 = p1.indexOf(';');
  if(idx2>-1){
    p1 = p1.substring(0,idx2);
  }
  return p1;
}

function getCookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(";");
  for (var i = 0; i < ca.length; i++) {
    var c = ca[i];
    while (c.charAt(0) == " ") c = c.substring(1, c.length);
    if (c.indexOf(nameEQ) == 0) {
      var d = c.substring(nameEQ.length, c.length);
      d = decodeURIComponent(d);
      return d;
    }
  }
  return undefined;
}

function getCookieM(name) {
  name = name + "";
  var re = new RegExp("(^| )" + name + "=([^;]+)", "gmi");
  var m = document.cookie.match(re);
  if (!!m) {
    m = m.pop();
    m = m.substring(m.indexOf("=") + 1);
    m = !!m ? decodeURIComponent(m) : m;
    return m;
  }
}

function getCookieW(name, str) {
  var str = str || document.cookie;
  var re = new RegExp("(?:^|; )("+name+"+?)(?:=([^;]*))?(?:;|$)", "gi");
  var value;
  var match;
  while ((match = re.exec(str))) {
    re.lastIndex = match.index + match.length - 1;
    var k = match[1];
    var v = decodeURIComponent(match[2]);
    !!v && (value = v);
  }

  return value;
}

document.cookie = "foo=bar";
document.cookie = "foo=nope;domain=measurethat.net";

Tests:

original
getCookie('foo')
Regex
getCookieM('foo')
regexloop
getCookieW('foo')
lastIndexOf
getCookieIX('foo')

Run results for: getCookie variations

original

Regex

regexloop

lastIndexOf