Benchmark: test12xxxx2 - MeasureThat.net

HTML Preparation code:

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

Tests:

1
var element = document.getElementById("foo"); element.className += " bar";
2
var element = document.getElementById("foo"); element.className = "bar";

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
1
2

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36

Browser/OS: Chrome 121 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
1	2849.4 Ops/sec
2	7897448.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**What is tested?**

The provided JSON represents a benchmark test case, which measures the performance of JavaScript code on different browsers and devices. The test cases are designed to measure the execution time of simple JavaScript code that interacts with the Document Object Model (DOM).

**Options compared:**

There are two options being compared:

1. **`element.className += " bar"`**: This line of code appends a string to the `className` property of an HTML element.
2. **`element.className = "bar"`**: This line of code assigns a single value to the `className` property of an HTML element.

**Pros and Cons:**

* **`element.className += " bar"`**:
	+ Pros:
		- More efficient, as it avoids creating a new string object and concatenating with a null or undefined value.
		- Better performance, especially for large strings or repeated appends.
	+ Cons:
		- May not be supported in older browsers or versions that don't implement the `+=` operator on strings.
* **`element.className = "bar"`**:
	+ Pros:
		- More readable and maintainable code.
		- Works everywhere, including older browsers and versions.
	+ Cons:
		- Less efficient, as it creates a new string object and assigns it to the `className` property.

**Library usage:**

None of the test cases use any external libraries. The test code is self-contained and only relies on the built-in DOM API.

**Special JS features or syntax:**

There are no special JavaScript features or syntax used in these test cases. They are written in plain JavaScript, using standard syntax and semantics.

**Other alternatives:**

If you were to write a new benchmark test case for this scenario, you might consider variations like:

* Measuring the performance of different string concatenation methods (e.g., `+`, `.concat()`, `Array.prototype.push()`).
* Testing the impact of using `let` or `const` instead of `var`.
* Comparing the performance of JavaScript code compiled to native machine code using tools like WebAssembly.

Keep in mind that these alternatives would likely require significant changes to the benchmark test case and might not be directly comparable to the original scenario.

Related benchmarks:

test12xxxx2 (version: 0)

Comparing performance of: 1 vs 2

Created: 2 years ago by: Guest

Jump to the latest result

1

2

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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