Benchmark: getElementById, querySelector, window

HTML Preparation code:

<div id="test">Test</div>

Tests:

getElementById
document.getElementById("test");
querySelector
document.querySelector("#test")
window
window["test"]
test
test

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getElementById
querySelector
window
test

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark test case on the MeasureThat.net website. The benchmark measures the execution time of different ways to access an element with the id "test" in HTML.

**Script and HTML Preparation Code**

The `Script Preparation Code` field is empty, which means that no custom script needs to be executed before running the benchmark. However, the `Html Preparation Code` field provides a basic HTML structure with a single `<div>` element having an id of "test".

**Individual Test Cases**

There are four test cases:

1. `getElementById`: Accesses the element using the `document.getElementById()` method.
2. `querySelector`: Accesses the element using the `document.querySelector()` method.
3. `window`: Accesses the element using the `window["test"]` syntax (more on this later).
4. `test`: A direct property access to the element, which is likely used as a baseline or a simple test.

**Options Compared**

The benchmark compares four different approaches:

1. **`document.getElementById()`**: Uses the `document` object and searches for an element by its id.
2. **`document.querySelector()`**: Uses the `document` object and searches for an element using a CSS selector (in this case, `#test`).
3. **`window["test"]`**: Directly accesses the element as if it were a property of the global `window` object.
4. **Direct Property Access (`test`)**: A simple test that directly accesses the element's value.

**Pros and Cons**

1. **`document.getElementById()`**:
	* Pros: Widely supported, easy to use, and fast for most cases.
	* Cons: Can be slow if the DOM is large or complex.
2. **`document.querySelector()`**:
	* Pros: More flexible than `getElementById`, can handle more complex selectors.
	* Cons: May be slower due to the complexity of the selector and the browser's CSS engine.
3. **`window["test"]`**:
	* Pros: Fast, direct access to the element (if it exists).
	* Cons: Only works if the element is directly accessible as a global variable; otherwise, can lead to unexpected behavior or errors.
4. **Direct Property Access (`test`)**:
	* Pros: Simple, fast, and easy to understand.
	* Cons: May not be supported by all browsers or environments.

**Libraries and Special Features**

None of the test cases use a library explicitly, but they rely on the `document` object and its methods. The `window["test"]` syntax uses dynamic property access, which is a feature supported by most modern JavaScript engines.

**Other Alternatives**

For comparing similar accessors, other options might include:

* Using the `elementFromPoint()` or `getElementsByClassName()` method
* Creating a custom function to search for elements based on a specific criteria

Keep in mind that these alternatives may have different performance characteristics and use cases compared to the original test cases.

In conclusion, this benchmark provides a good starting point for understanding the performance differences between various ways of accessing an element with a specific id in JavaScript. The results can help developers choose the most efficient approach for their use case.

Related benchmarks:

getElementById, querySelector, window (version: 0)

Comparing performance of: getElementById vs querySelector vs window vs test

Created: 8 years ago by: Guest

Jump to the latest result

getElementById

querySelector

window

test

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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