Benchmark: my Array.from() vs new Array()

Tests:

new Array()
new Array(500).fill(null)
Array.from()
Array.from({ length: 500 }, () => null)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new Array()
Array.from()

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**What is being tested?**

The provided benchmark tests two ways to create filled arrays in JavaScript:

1. **new Array()**: This method creates an empty array and then fills it with null values using the `fill()` method.
2. **Array.from()**: This method creates a new array from an iterable (in this case, an object) and fills it with null values using a callback function.

**Options being compared**

The two options being compared are:

* `new Array()`: A traditional way of creating arrays in JavaScript.
* `Array.from()`: A more modern way of creating arrays, introduced in ECMAScript 2015 (ES6).

**Pros and cons of each approach:**

1. **new Array()**:
	* Pros:
		+ Wide browser support across all versions of Internet Explorer to Chrome.
		+ Easy to read and write.
	* Cons:
		+ Can be slower than `Array.from()` due to the overhead of creating an empty array and then filling it.
2. **Array.from()**:
	* Pros:
		+ More concise and expressive code.
		+ Can be faster than `new Array()` because it avoids the overhead of creating an empty array.
	* Cons:
		+ Requires ECMAScript 2015 (ES6) or later support, which may not be available in older browsers.

**Library and purpose**

In this benchmark, a library is not explicitly mentioned. However, `Array.from()` uses a built-in JavaScript function to create an array from an iterable.

**Special JS feature or syntax**

There are no special JavaScript features or syntaxes used in this benchmark other than the use of ECMAScript 2015 (ES6) syntax for `Array.from()`.

Latest run results:

Run details: (Test run date: 7 days ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser/OS: Chrome 130 on Linux

View result in a separate tab

Test name	Executions per second
new Array()	1396500.6 Ops/sec
Array.from()	54245.7 Ops/sec

Related benchmarks:

my Array.from() vs new Array() (version: 0)

Testing the difference between creating filled arrays.

Comparing performance of: new Array() vs Array.from()

Created: 2 years ago by: Guest

Jump to the latest result

new Array()

Array.from()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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