Benchmark: addFunction vs classList

HTML Preparation code:

<div id="foo"></div>

Script Preparation code:

function addClass(el, classNames)
{
  if (!classNames) { return; }
 
        if (!Object.prototype.toString.call(classNames) === "[object Array]")
        {
            classNames = classNames.split(' ');
        }
        var className = el.getAttribute("class") || "";
 
        var i, classMap = {}, currentClasses = [], length;
 
        if (className !== null)
        {
            currentClasses = className.split(" ");
 
            length = currentClasses.length;
            for (i = 0; i < length; i++)
            {
                if (currentClasses[i] !== "")
                {
                    classMap[currentClasses[i]] = "";
                }
            }
        }
 
        var changed = false, trimmedName;
        var newAdded = [];
        length = classNames.length;
        for (i = 0; i < length; i++)
        {
            trimmedName = classNames[i].trim();
            if ((trimmedName.length > 0) && !(trimmedName in classMap))
            {
                currentClasses.push(trimmedName);
                newAdded.push(trimmedName);
                classMap[trimmedName] = "";
                changed = true;
            }
        }
 
        if (changed)
        {
            el.setAttribute("class", currentClasses.join(" ").trim());
        }
 
        return newAdded;
}

Tests:

addClass function
var element = document.getElementById("foo"); var i = 1000; while (i--) { addClass(element, "bar"); }
classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.classList.add("bar"); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
addClass function
classList

Fastest: N/A

Slowest: N/A

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Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko

Browser/OS: IE 11 on Windows

View result in a separate tab

Test name	Executions per second
addClass function	426.4 Ops/sec
classList	2794.9 Ops/sec

addFunction vs classList (version: 0)

Comparing performance of: addClass function vs classList

Created: 3 years ago by: Guest

Jump to the latest result

addClass function

classList

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A