Benchmark: Javascript Array.prototype.push vs index assignment

Tests:

Array.prototype.push
const arr = [1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3] arr.push(4)
index assignment
const arr = [1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3] arr[arr.length] = 4

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.push
index assignment

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:146.0) Gecko/20100101 Firefox/146.0

Browser/OS: Firefox 146 on Windows

View result in a separate tab

Test name	Executions per second
Array.prototype.push	40054316.0 Ops/sec
index assignment	40177384.0 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark measures the performance difference between two approaches:

1. **Array.prototype.push**: Using the `push()` method to add an element to the end of an array.
2. **Index assignment**: Directly assigning a value to the last index of an array.

**What is being compared?**

The benchmark compares the performance of these two approaches on the same array size (200 elements). The goal is to determine which approach is faster and more efficient.

**Pros and Cons of each approach:**

1. **Array.prototype.push**:
	* Pros:
		+ Concise and readable syntax.
		+ Easy to maintain and extend.
	* Cons:
		+ May involve additional overhead due to the method call and argument passing.
2. **Index assignment**:
	* Pros:
		+ Direct access to the array's underlying storage, potentially reducing overhead.
		+ Can be faster for smaller arrays or when performance is critical.
	* Cons:
		+ Less readable and maintainable syntax (especially for larger arrays).
		+ May lead to memory fragmentation issues if not used carefully.

**Other considerations:**

* The benchmark uses a fixed array size, which may not accurately represent real-world scenarios where array sizes can vary greatly.
* There is no consideration for the actual data being pushed or assigned; only the operation itself is being measured.

**Library and special JS features used in this benchmark:**

None of the individual test cases use any external libraries. However, JavaScript has a few special features that might influence the results:

* The `let` keyword (used in the script preparation code) was introduced in ECMAScript 2015 (ES6). Its use may affect performance or syntax highlighting.
* The `const` keyword (also used in the script preparation code) is another ES6 feature. It can have implications for memory management and optimization.

**Other alternatives:**

To further explore this benchmark, you could consider adding other approaches, such as:

1. Using a different data structure, like a linked list or a sparse array.
2. Using a different programming language or implementation (e.g., TypeScript, Node.js, etc.).
3. Incorporating additional factors, like concurrency, parallelism, or memory constraints.

By expanding the scope of the benchmark, you can gain more insights into the trade-offs and complexities involved in these two approaches, as well as other performance optimizations in JavaScript development.

Related benchmarks:

Javascript Array.prototype.push vs index assignment (version: 0)

Comparing performance of: Array.prototype.push vs index assignment

Created: 3 years ago by: Guest

Jump to the latest result

Array.prototype.push

index assignment

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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