Benchmark: Array.from 1e6 vs 1e3

Tests:

1e6
var other = Array.from({ length: 1e6 }, (_, i) => i);
1e3
var other = Array.from({ length: 1e3 }, (_, i) => i);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
1e6
1e3

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**

The benchmark definition is a simple JavaScript statement that creates an array using the `Array.from()` method with a specific length. The difference between two test cases lies in the length of the array: one is 1 million (1e6) elements, and the other is 3000 (1e3) elements.

**Options being compared**

The benchmark is comparing the performance of `Array.from()` with different lengths:

* `Array.from({ length: 1e6 }, (_, i) => i);` creates an array of 1 million elements.
* `Array.from({ length: 1e3 }, (_, i) => i);` creates an array of 3000 elements.

**Pros and Cons**

The choice of array length affects the performance of `Array.from()`:

* Creating a large array (1e6 elements) can be slower due to memory allocation and iteration overhead.
* Creating a small array (1e3 elements) is typically faster since it requires less memory and fewer iterations.

However, the actual performance difference between these two options may not be significant unless working with extremely large datasets. In general, creating arrays with moderate sizes (thousands to tens of thousands of elements) should be efficient enough for most use cases.

**Library usage**

In both benchmark definitions, `Array.from()` is used as a function to create an array. This is a built-in JavaScript method that was introduced in ECMAScript 2015 (ES6).

**Special JS features/syntax**

There are no special JavaScript features or syntax used in these benchmark definitions beyond the standard `Array.from()` method.

**Other alternatives**

If you need to compare the performance of different array creation methods, you might consider using other approaches:

* Using a `Array` constructor with an initial length: `new Array(1e6);`
* Using the spread operator (`...`) to create an array: `[...new Array(1e6)].map((_, i) => i);`
* Using a loop to create an array: `for (var i = 0; i < 1e6; i++) { var arr[i] = i; }`

These alternatives might exhibit different performance characteristics depending on the specific use case and JavaScript engine.

Keep in mind that creating large arrays can be memory-intensive, so it's essential to consider the trade-offs between performance and memory usage when choosing an array creation method.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:79.0) Gecko/20100101 Firefox/79.0

Browser/OS: Firefox 79 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
1e6	56.6 Ops/sec
1e3	80172.6 Ops/sec

Related benchmarks:

Array.from 1e6 vs 1e3 (version: 0)

Comparing performance of: 1e6 vs 1e3

Created: 4 years ago by: Guest

Jump to the latest result

1e6

1e3

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):