Benchmark: comparing push vs spread one by one

Tests:

Push
const elements = Array(1000).map(i => { id: i }); const array = []; elements.forEach((element) => array.push(element));
Spread
const elements = Array(1000).map(i => { id: i }); let array = []; elements.forEach((element) => array = [...array, element]);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Push
Spread

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 9 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 YaBrowser/24.7.0.0 Safari/537.36

Browser/OS: Yandex Browser 24 on Linux

View result in a separate tab

Test name	Executions per second
Push	385705.2 Ops/sec
Spread	388589.4 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**Overview**
The benchmark is designed to compare two approaches for adding elements to an array: using the `push()` method versus using the spread operator (`...`). The test creates an array of 1000 elements with a unique ID, then iterates through each element and adds it to another empty array. The benchmark measures the execution time of both approaches.

**Options compared**

There are two options being compared:

1. **Push**: Using the `push()` method to add elements to an array.
2. **Spread**: Using the spread operator (`...`) to add elements to an array.

**Pros and Cons**

* **Push**:
	+ Pros: The `push()` method is a built-in JavaScript method that is widely supported and has been around for a long time, making it a familiar choice for developers.
	+ Cons: For large arrays, the `push()` method can be slower than other approaches because it involves appending elements to the end of the array one by one. This can lead to a higher number of cache misses and slower performance.
* **Spread**:
	+ Pros: The spread operator (`...`) is a newer feature that was introduced in ECMAScript 2015 (ES6). It can be faster than `push()` for large arrays because it avoids the need for appending elements one by one, reducing cache misses and improving performance.
	+ Cons: However, the spread operator is not supported in older browsers or JavaScript environments. Additionally, some developers may find it less familiar or less efficient due to its novelty.

**Library usage**
The benchmark uses an array of 1000 elements with a unique ID, which suggests that no external libraries are being used for this specific test case.

**Special JS features/syntax**
There is no mention of any special JavaScript features or syntax in the provided benchmark code. The language and syntax used are standard JavaScript.

**Alternatives**

Other alternatives for adding elements to an array might include:

* Using `concat()` method instead of `push()`
* Using `set` object instead of arrays
* Using a library like Lodash's `insertAt` function

However, it's worth noting that the spread operator (`...`) has become increasingly popular and efficient in recent years, making it a strong contender for this type of benchmark.

I hope this explanation helps software engineers understand what is being tested in this benchmark!

Related benchmarks:

comparing push vs spread one by one (version: 0)

Comparing performance of: Push vs Spread

Created: 5 years ago by: Guest

Jump to the latest result

Push

Spread

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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