Benchmark: document vs. var for document

HTML Preparation code:

<div id="test1"></div>
<div id="test2"></div>
<div id="test3"></div>
<div id="test4"></div>
<div id="test5"></div>

Tests:

document
document.getElementById('test1'); document.getElementById('test2'); document.getElementById('test3'); document.getElementById('test4'); document.getElementById('test5');
var for document
var d = document; d.getElementById('test1'); d.getElementById('test2'); d.getElementById('test3'); d.getElementById('test4'); d.getElementById('test5');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
document
var for document

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark, hosted on MeasureThat.net, tests the performance of two approaches to access the `document` object in JavaScript: using the `var` keyword or directly accessing it as a property.

**Options Compared**

Two test cases are compared:

1. **Directly accessing `document`**: This approach uses the `document` object without declaring a variable.
2. **Using `var` to declare a reference to `document`**: This approach declares a variable `d` and assigns the `document` object to it.

**Pros and Cons**

### Directly Accessing `document`

Pros:

* Simplistic and straightforward way to access the `document` object
* Less code to write

Cons:

* May not be as efficient due to potential type coercion or scope resolution issues (e.g., if `d` is a function)
* May lead to unexpected behavior if not used carefully

### Using `var` to Declare a Reference to `document`

Pros:

* Can improve performance by avoiding the overhead of type coercion and scope resolution
* Can provide better control over the variable's scope and lifetime

Cons:

* Requires an additional line of code to declare the variable
* May lead to unnecessary complexity if not used thoughtfully

**Library Usage**

None of the test cases use a library. The benchmark only relies on standard JavaScript functionality.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntax used in this benchmark. Both approaches use basic JavaScript syntax and semantics.

**Other Alternatives**

If you wanted to test other approaches, you might consider adding more test cases, such as:

* Using a different variable declaration mechanism (e.g., `let`, `const`, or arrow functions)
* Using a different way to access the `document` object (e.g., via `window.document`)
* Comparing performance with other browser engines (e.g., Firefox, Edge)

Keep in mind that these alternatives might not provide new insights into the fundamental trade-offs between directly accessing `document` and using `var` to declare a reference.

Related benchmarks:

document vs. var for document (version: 0)

Comparing performance of: document vs var for document

Created: 5 years ago by: Registered User

Jump to the latest result

document

var for document

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):