Benchmark: Dom benchmark - MeasureThat.net

HTML Preparation code:

<div id="i1">
  <div id="i2">
    <div id="i4" class="c1">
      <div class="c5">
        <div class="c4">

        </div>
        <div class="c5">

        </div>
      </div>
    </div>
    <div class="c7">
      <div class="c6">

      </div>
    </div>
    <div id="i3" class="c2">
      <div class="c3">
        <div class="c4">
          <div class="c8">
            <span>
				Find me
            </span>
          </div>
        </div>
        <div class="c5">

        </div>
      </div>
    </div>
  </div>
</div>

Script Preparation code:

function test1() {
  return document.getElementById('i3').querySelector('span');
}

function test2() {
  var e = document.getElementById('i3');
  return e ? e.querySelector('span') : null;
}

function test3() {
  return document.getElementById('i4').querySelector('span');
}

function test4() {
  var e = document.getElementById('i4');
  return e ? e.querySelector('span') : null;
}

function test5() {
  return document.querySelector('span');
}

Tests:

one-liner found
var r = test1();
if breakout found
var r = test2();
one-liner not found
var r = test3();
if breakout not found
var r = test4();
single found
var r = test5();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
one-liner found
if breakout found
one-liner not found
if breakout not found
single found

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):

LLMs can make mistakes. Check important info.

Let's dive into explaining what's tested in the provided JSON benchmark.

**Benchmark Overview**

The benchmark consists of five test cases, each measuring the performance of finding a specific HTML element using different methods:

1. `test1`: One-liner found (using `querySelector` on an element with an ID)
2. `test2`: If breakout found (using `?` operator for null checks)
3. `test3`: One-liner not found
4. `test4`: If breakout not found
5. `test5`: Single found (using `querySelector` without any condition)

**Options Compared**

Each test case compares two different approaches to find an element:

* In `test1`, `test3`, and `test5`, the comparison is between using a one-liner (`document.getElementById('id').querySelector('span')`) versus not finding the element at all (i.e., returning null or undefined).
* In `test2` and `test4`, the comparison is between two different null checks: using an explicit check (`e ? e.querySelector('span') : null`) versus a conditional expression (`e ? e.querySelector('span') : null`).

**Pros and Cons**

Here's a brief analysis of each approach:

1. One-liner:
	* Pros: concise, efficient
	* Cons: can be less readable, may not handle all edge cases (e.g., no element found)
2. Null checks:
	* Pros: explicit, safe, and easy to understand
	* Cons: may add overhead due to the conditional check

**Library**

In this benchmark, the `querySelector` method is used from the DOM API. This library provides a standard way to query elements in HTML documents.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntax mentioned in the benchmark. The code uses only standard JavaScript syntax and libraries (DOM API).

**Other Alternatives**

If you were to modify the benchmark, here are some alternative approaches you could consider:

* Using `querySelectorAll` instead of `querySelector`
* Adding a timeout for non-existent elements
* Comparing different element selection methods (e.g., `getElementById`, `getElementsByClassName`)
* Incorporating CSS selectors or attribute queries

Keep in mind that these alternatives would change the nature of the benchmark, so it's essential to carefully evaluate which changes are relevant and meaningful.

Overall, the benchmark provides a good starting point for measuring performance differences between various approaches to find elements in HTML documents.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/112.0

Browser/OS: Firefox 112 on Windows

View result in a separate tab

Test name	Executions per second
one-liner found	3826284.0 Ops/sec
if breakout found	3839005.5 Ops/sec
one-liner not found	3737358.2 Ops/sec
if breakout not found	3746461.8 Ops/sec
single found	4240275.0 Ops/sec

Related benchmarks:

Dom benchmark (version: 0)

Comparing performance of: one-liner found vs if breakout found vs one-liner not found vs if breakout not found vs single found

Created: 7 years ago by: Guest

Jump to the latest result

one-liner found

if breakout found

one-liner not found

if breakout not found

single found

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):