Benchmark: array comparison 4

Tests:

fill
const miArray1 = Array(100).fill().map((el, i)=> i)
spread
const miArray2 = [...Array(100)].map((el, i)=> i)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
fill
spread

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	1356734.5 Ops/sec
spread	1807844.6 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases to understand what's being tested, compared, and their pros and cons.

**Benchmark Definition:**

The benchmark definition is empty (`"Description": null`), but we have two `Script Preparation Code`s and two `Html Preparation Code`s. Typically, a benchmark definition would include the script(s) or code that needs to be executed during the test.

Given the provided `Test Name`s (e.g., "fill" and "spread"), it appears that the benchmark is comparing the performance of creating an array with `Array().fill()` versus `Array.prototype.fill()` methods.

**Individual Test Cases:**

There are two test cases:

1. **`fill`**: The benchmark definition uses the `const miArray1 = Array(100).fill().map((el, i) => i)` script preparation code. This creates an array with 100 elements using the `fill()` method and then maps over it to create a new array with indices.
2. **`spread`**: The benchmark definition uses the `const miArray2 = [...Array(100)].map((el, i) => i)` script preparation code. This is similar to the first test case but uses the spread operator (`...`) to create an array with 100 elements and then maps over it.

**Comparison:**

The two test cases are comparing the performance of creating an array using `Array().fill()` versus `Array.prototype.fill()` methods, both followed by mapping over the resulting array. This comparison is likely being done to determine which method is faster or more efficient for this specific use case.

**Pros and Cons:**

1. **`Array().fill()`**:
	* Pros: Can be simpler and more concise.
	* Cons: May have additional overhead due to creating an intermediate array before mapping.
2. **`Array.prototype.fill()`**:
	* Pros: Can avoid creating an intermediate array, potentially reducing overhead.
	* Cons: Requires the `map()` method or a for loop after filling, which may add complexity.

It's worth noting that the actual performance difference between these two methods might be small and dependent on various factors, such as JavaScript engine optimizations, browser versions, and hardware configurations.

**Library:**

None of the provided benchmark definitions use any external libraries. However, if you were to compare implementations using a library like Lodash or Ramda, it would likely involve importing those libraries and using their `fill()` or equivalent methods.

**Special JS Feature/Syntax:**

There are no special JavaScript features or syntax used in these test cases that would require additional explanation.

**Other Alternatives:**

Some alternative ways to create an array with a fixed number of elements include:

* Using the `Array.from()` method (introduced in ECMAScript 2015) with a spread operator.
* Creating an array using `Math.pow()` and the ternary operator (`i % 2 === 0 ? ... : ...`).
* Using a for loop to create the array.

These alternatives might be worth exploring if you're interested in further benchmarking or optimizing JavaScript performance.

Related benchmarks:

array comparison 4 (version: 0)

Comparing performance of: fill vs spread

Created: 4 years ago by: Guest

Jump to the latest result

fill

spread

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):