Benchmark: Array constructor vs literal performance, 12345

Tests:

Array constructor - 10 items
var arr = new Array();
Array literal (assign by index) - 10 items
var arr = [];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array constructor - 10 items
Array literal (assign by index) - 10 items

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser/OS: Chrome 130 on Windows

View result in a separate tab

Test name	Executions per second
Array constructor - 10 items	16623015.0 Ops/sec
Array literal (assign by index) - 10 items	234986352.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the test cases and explain what is being tested.

**What are we testing?**

We're comparing two approaches to create an empty array in JavaScript: using the `Array` constructor (`new Array()`) versus literal syntax (`[]`). The goal is to measure which approach performs better.

**Options compared:**

1. **Array constructor**: `var arr = new Array();`
2. **Literal syntax**: `var arr = [];`

**Pros and Cons of each approach:**

* **Array constructor**:
	+ Pros:
		- Can be used to create arrays with a specific length.
		- Can be used to initialize properties on the array object.
	+ Cons:
		- Requires creating an empty object and then pushing elements into it, which can lead to additional overhead.
		- May involve more code to achieve the same result as literal syntax.
* **Literal syntax**:
	+ Pros:
		- More concise and readable.
		- Can be used directly in most contexts.
	+ Cons:
		- Limited flexibility compared to `Array` constructor.

**Other considerations:**

* The test cases use a fixed number of items (10) in the array, which might not accurately reflect real-world scenarios where arrays can have varying lengths.
* The test doesn't consider other factors that could affect performance, such as the type of data being stored in the array or the browser's implementation.

**Special JavaScript features/syntax:**

There are no special JavaScript features or syntax used in this benchmark.

**Libraries and dependencies:**

None mentioned in the provided information.

**Alternatives:**

Other approaches to create an empty array include:

* Using the `Array()` function with the `new` keyword (e.g., `var arr = new Array(10)`).
* Using a polyfill or transpiler like Babel, which can transpile `[]` into `new Array()`.
* Using a library like Lodash, which provides an empty array factory function (`_.empty()`).

The test cases provided by MeasureThat.net focus on the fundamental difference between using the `Array` constructor and literal syntax to create an empty array.

Related benchmarks:

Array constructor vs literal performance, 12345 (version: 0)

Comparing performance of: Array constructor - 10 items vs Array literal (assign by index) - 10 items

Created: 3 years ago by: Guest

Jump to the latest result

Array constructor - 10 items

Array literal (assign by index) - 10 items

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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