Benchmark: array_creation_comparison

Tests:

fill
const miArray = Array(100).fill().map((el, i)=> i)
from
const miArray = Array.from(Array(100), (el, i) => i)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
fill
from

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.116 Safari/537.36

Browser/OS: Chrome 83 on Windows

View result in a separate tab

Test name	Executions per second
fill	1414385.0 Ops/sec
from	292661.6 Ops/sec

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 on MeasureThat.net.

The provided benchmark definition json and individual test cases are designed to compare two different approaches for creating an array in JavaScript: `Array.prototype.fill()` and `Array.from()`. We'll break down each approach, their pros and cons, and discuss any libraries or special features used.

**Approach 1: Using `Array.prototype.fill()`**

The first benchmark definition uses the `fill()` method to create an array:
```javascript
const miArray = Array(100).fill().map((el, i) => i);
```
Here's what happens:

* `Array(100)` creates a new array with 100 elements.
* `.fill()` sets all elements of the array to a default value (in this case, undefined).
* `.map()` applies a transformation function to each element in the array, returning a new array with the transformed values.

Pros:

* Simple and concise syntax.
* Fast execution since it's a built-in method.

Cons:

* Creates an intermediate array with 100 elements filled with the default value (undefined). This can be wasteful for large arrays.
* May not be as efficient as other approaches since it involves multiple steps.

**Approach 2: Using `Array.from()`**

The second benchmark definition uses the `from()` method to create an array:
```javascript
const miArray = Array.from(Array(100), (el, i) => i);
```
Here's what happens:

* `Array(100)` creates a new array with 100 elements.
* `Array.from()` creates a new array by mapping over the existing array using the provided function.
* `(el, i) => i` is the transformation function that returns each element's index.

Pros:

* More efficient than `fill()` since it avoids creating an intermediate array.
* Can be faster for large arrays since it uses a more direct approach.

Cons:

* Requires additional dependencies (e.g., ECMAScript 2015 features).
* May not be as simple to read or understand for developers unfamiliar with `from()`.

**Library and Special Features**

Both benchmark definitions use the following libraries or special features:

* No external libraries are required.
* JavaScript's built-in `Array.prototype.fill()` method is used in one approach, while `Array.from()` is used in the other.

**Other Alternatives**

Additional approaches for creating arrays in JavaScript include:

* Using a simple array comprehension: `[...new Array(100)].map((el, i) => i);`
* Using the spread operator (`...`): [...new Array(100).keys()];
* Using a `for` loop or `forEach()` method to create an array.

Each of these approaches has its own pros and cons, and may be more suitable for specific use cases. However, since this benchmark is specifically designed to compare two methods, it's likely that the chosen approaches are optimized for performance and simplicity.

**Conclusion**

In summary, MeasureThat.net's `array_creation_comparison` benchmark tests the performance of two different approaches for creating arrays in JavaScript: `Array.prototype.fill()` and `Array.from()`. The pros and cons of each approach were discussed, along with any libraries or special features used. Understanding these approaches can help developers choose the most suitable method for their specific use cases.

Related benchmarks:

array_creation_comparison (version: 0)

Comparing performance of: fill vs from

Created: 4 years ago by: Guest

Jump to the latest result

fill

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):