Benchmark: Array push vs Array fill

Tests:

for
const childCount = 10000; const rows = Array(childCount); for (let i = 0; i < childCount; i += 1) { rows[i]; } return rows;
fill
const childCount = 10000; return Array(childCount).fill({})

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
fill

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The provided benchmark measures the performance difference between two approaches to create an array with 10,000 elements: using a `for` loop and using the `fill()` method.

**Options being compared:**

1. **Array push vs Array fill**: The two main options being compared are:
	* Using a `for` loop to create an array by pushing elements into it (`rows[i] = {};`).
	* Using the `fill()` method to create an array with a specified value (`Array(childCount).fill({})`).
2. **Browser and Device**: The benchmark also measures performance across different browsers (Chrome 101) and devices (Desktop, Linux).

**Pros and Cons of each approach:**

1. **Array push**:
	* Pros:
		+ More control over the creation process.
		+ Can be beneficial for small arrays where `fill()` might create a large array in memory.
	* Cons:
		+ More overhead due to the loop and assignment statements.
		+ May lead to slower performance due to the repeated access to the array elements.
2. **Array fill**:
	* Pros:
		+ Faster performance since it avoids the loop and repeated assignments.
		+ Can be beneficial for large arrays where `fill()` can create an array in a single operation.
	* Cons:
		+ Less control over the creation process.
		+ May not work as expected if you need to modify individual elements.

**Library usage:**

None of the provided benchmark scripts use any external libraries. The only library-like functionality is used by `Array` itself, which provides methods like `fill()` and `push()`.

**Special JS feature or syntax:**

There are no special JavaScript features or syntaxes being tested in this benchmark. Both approaches rely on standard JavaScript language constructs.

**Benchmark preparation code:**

The script preparation code for both benchmarks is empty, indicating that MeasureThat.net doesn't require any setup or initialization code to run the benchmarks.

**Other alternatives:**

If you're interested in exploring alternative approaches to create arrays, here are a few examples:

1. **Using `Array.from()`**: This method creates an array from an iterable or an array-like object.
2. **Using `new Array(size)`**: This constructor creates an empty array of the specified size.

These alternatives might offer better performance or more control over the creation process in certain scenarios, but they may not be as straightforward to use as the `fill()` method or a simple loop.

I hope this explanation helps you understand what's being tested on MeasureThat.net!

Related benchmarks:

Array push vs Array fill (version: 0)

Comparing performance of: for vs fill

Created: 4 years ago by: Guest

Jump to the latest result

for

fill

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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