Benchmark: Array of undefined

Script Preparation code:

var pushed = [];
for (let i = 0; i < 1000; i++) pushed.push(undefined);
var filled = (new Array(1000)).fill(undefined);

Tests:

Create: Push
const a = []; for(let i = 0; i < 1000; i++) a.push(undefined);
Create: Fill
const a = (new Array(1000)).fill(undefined);
Read: Push
pushed[Math.floor(Math.random()*1000)];
Read: Fill
filled[Math.floor(Math.random()*1000)];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Create: Push
Create: Fill
Read: Push
Read: Fill

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.128 Safari/537.36

Browser/OS: Chrome 89 on Mac OS X 10.14.6

View result in a separate tab

Test name	Executions per second
Create: Push	6811.4 Ops/sec
Create: Fill	295501.7 Ops/sec
Read: Push	2635804.0 Ops/sec
Read: Fill	2712725.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and considered.

**Benchmark Overview**

The provided benchmark consists of four test cases:

1. Creating an array with `push()` (Create: Push)
2. Creating an array with `fill()` (Create: Fill)
3. Reading elements from an array created with `push()` (Read: Push)
4. Reading elements from an array created with `fill()` (Read: Fill)

Each test case has a corresponding JavaScript code snippet.

**Options Compared**

In this benchmark, the following options are compared:

* **Push vs. Fill**: Two ways to create arrays of undefined values.
	+ **Pros of Push**: Allows for more control over individual elements, can be used with other methods like `unshift()` or `splice()`.
	+ **Cons of Push**: Can be slower than using `fill()`, as it involves iterating over the array to add elements.
* **Read Performance**: Reading elements from arrays created with different methods.

**Library Used**

None of the test cases explicitly use a library. However, modern JavaScript engines like V8 (used by Chrome) have built-in optimizations and features that can affect performance.

**Special JS Features or Syntax**

There are no special JS features or syntax used in this benchmark. The code snippets only utilize standard JavaScript constructs.

**Other Considerations**

When interpreting the results, consider the following factors:

* **Array size**: All test cases create arrays of 1000 elements.
* **Browser and OS**: Results are reported for Chrome 89 on Mac OS X 10.14.6.
* **Execution frequency**: The number of executions per second is a good indicator of performance.

**Results Interpretation**

Looking at the latest benchmark result, we can see that:

* **Read: Fill** consistently outperforms **Read: Push**, indicating that using `fill()` to create arrays might be faster for read operations.
* **Create: Fill** performs better than **Create: Push**, suggesting that using `fill()` to create arrays is also more efficient.

Keep in mind that these results are specific to Chrome 89 on Mac OS X 10.14.6 and may not generalize to other browsers, OS versions, or execution scenarios.

**Other Alternatives**

If you're interested in exploring alternative benchmarking frameworks or approaches, consider the following options:

* **Benchmarking libraries**: Libraries like `benchmark.js` provide more features and flexibility for writing benchmarks.
* **Micro-benchmarking tools**: Tools like `micro-benchmarks` offer a simpler, more concise way to write microbenchmarks.

However, the provided Benchmark Definition and test cases already offer a clear and concise approach to benchmarking JavaScript array operations.

Related benchmarks:

Array of undefined (version: 3)

Comparing performance of: Create: Push vs Create: Fill vs Read: Push vs Read: Fill

Created: 3 years ago by: Registered User

Jump to the latest result

Create: Push

Create: Fill

Read: Push

Read: Fill

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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