Benchmark: Array constructor vs literal

Tests:

Array constructor - 1000 items
var n = 1000; var arr = new Array(n); for (var i = 0; i < n; i++) { arr[i] = i; }
Array literal - 1000 items
var n = 1000; var arr = []; for (var i = 0; i < n; i++) { arr.push(i); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array constructor - 1000 items
Array literal - 1000 items

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.36 Edg/136.0.0.0

Browser/OS: Chrome 136 on Windows

View result in a separate tab

Test name	Executions per second
Array constructor - 1000 items	1871444.1 Ops/sec
Array literal - 1000 items	368060.6 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in the provided JSON benchmark.

**Test Case Explanation**

The two test cases are designed to compare the performance of creating an array using the `new Array()` constructor versus using literal syntax (`[]`). The test case for each method creates a large array (1,000 elements) and fills it with sequential integers.

**Options Compared**

* **Array Constructor**: `new Array(n)`
	+ Pros:
		- Can be more readable in certain contexts (e.g., when initializing arrays with multiple dimensions).
	+ Cons:
		- May incur additional overhead due to the creation of a new object.
		- May not work as expected if the array needs to be cloned or modified frequently.
* **Literal Syntax**: `[]`
	+ Pros:
		- Typically faster and more efficient, as it avoids the overhead of creating an object.
		- Works well with modern JavaScript features like `push()` and `concat()`.
	+ Cons:
		- May be less readable in certain contexts.

**Library Usage**

None. There is no explicit library usage in these test cases.

**Special JS Features or Syntax**

There are no special JavaScript features or syntax used in these test cases, but it's worth noting that the use of `new Array()` and literal syntax (`[]`) is a common pattern in JavaScript.

**Other Alternatives**

If you were to rewrite these test cases using other array creation methods, such as:

* `Array.from()`: This method creates an array from an iterable or an array-like object.
* `Array.prototype.slice()`: This method returns a shallow copy of a portion of an array.
* Other libraries or frameworks (e.g., React's `useArray` hook)

Keep in mind that the performance differences between these methods may vary depending on the specific use case and environment. The test results provided by MeasureThat.net likely take into account various factors, including browser version, device platform, and operating system.

In general, when deciding between array creation methods, consider the trade-offs between readability, maintainability, and performance.

Related benchmarks:

Array constructor vs literal (version: 0)

Comparing performance of: Array constructor - 1000 items vs Array literal - 1000 items

Created: 9 years ago by: Guest

Jump to the latest result

Array constructor - 1000 items

Array literal - 1000 items

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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