Benchmark: Test push, spread, concat

Tests:

push
let first = []; let second = []; for (var i; i < 10000; i++) { first.push(i); second.push(i); } first.push(...second);
concat
let first = []; let second = []; for (var i; i < 10000; i++) { first.push(i); second.push(i); } first = first.concat(second);
spread
let first = []; let second = []; for (var i; i < 10000; i++) { first.push(i); second.push(i); } first = [...first, ...second];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
push
concat
spread

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

The provided benchmark is designed to test the performance of three different ways of merging or concatenating arrays in JavaScript:

1. **Push with spread operator (`...`)**: This approach uses the spread operator to merge two arrays by spreading the second array's elements into the first array using the `push()` method.
2. **Concatenation using `concat()`**: This approach uses the `concat()` method to merge two arrays by creating a new array and adding the elements of both arrays to it.
3. **Spread operator with array destructuring (`[...first, ...second]`)**: This approach uses the spread operator to merge two arrays by creating a new array that includes all elements from both arrays.

Here are some pros and cons of each approach:

* **Push with spread operator (`...`)**:
	+ Pros: Simple, concise, and readable. It's also a relatively fast method since it avoids the creation of a new array.
	+ Cons: Some older browsers may not support the spread operator or have performance issues with it.
* **Concatenation using `concat()`**:
	+ Pros: Widely supported across most browsers and devices. The `concat()` method is also quite efficient, especially when merging large arrays.
	+ Cons: It can be slower than the push with spread operator approach since it involves creating a new array and copying elements from one array to another.
* **Spread operator with array destructuring (`[...first, ...second]`)**:
	+ Pros: Fast and concise. This method avoids the creation of an intermediate array, making it suitable for large arrays.
	+ Cons: Not supported in older browsers or Internet Explorer. It also requires modern JavaScript features like rest syntax.

Other considerations:

* The use of `var` instead of `let` or `const` may impact performance due to variable hoisting and scope issues.
* For loop vs. array methods (e.g., `for...of`) may have different performance characteristics depending on the browser and the specific use case.
* The benchmark results show that the push with spread operator approach is currently the fastest, followed by concatenation using `concat()`, and then the spread operator with array destructuring.

Library/Functionality usage:

None of the provided benchmark definitions include any libraries or external functions. However, it's worth noting that if a library like Lodash or Ramda were used to implement these operations, it could impact performance due to the added overhead of the library.

Special JavaScript features or syntax:

The push with spread operator approach uses modern JavaScript features like rest syntax (`[...first, ...second]`) and the spread operator (`...`). The other two approaches do not rely on any special features.

Latest run results:

Run details: (Test run date: 2025 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.162 Safari/537.36

Browser/OS: Chrome 65 on Mac OS X 10.13.3

View result in a separate tab

Test name	Executions per second
push	59707748.0 Ops/sec
concat	3680559.0 Ops/sec
spread	78857048.0 Ops/sec

Related benchmarks:

Test push, spread, concat (version: 0)

Comparing performance of: push vs concat vs spread

Created: 6 years ago by: Guest

Jump to the latest result

push

concat

spread

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):