Benchmark: push spread vs push foreach

Tests:

push spread
const dest = [1, 2] const src = [1, 2, 3, 4] dest.push(...src)
foreach push
const dest = [1, 2] const src = [1, 2, 3, 4] src.forEach((e) => dest.push(e))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
push spread
foreach push

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Windows

View result in a separate tab

Test name	Executions per second
push spread	73539152.0 Ops/sec
foreach push	67487232.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to help explain what's being tested in the provided benchmark.

**Benchmark Definition**

The benchmark is testing two approaches for appending elements from an array to another array:

1. **Push Spread**: Using the spread operator (`...`) to append all elements from one array to another.
2. **Foreach Push**: Iterating over each element of one array and manually pushing it onto another array.

**Options Compared**

The benchmark is comparing the performance of these two approaches on an array containing three elements: `[1, 2]` and a larger array `src` with four additional elements (`[3, 4]`). The test aims to determine which approach is faster.

**Pros and Cons**

* **Push Spread**: This approach has several advantages:
	+ It's concise and easier to read.
	+ It's generally faster since it avoids the overhead of iterating over each element.
	+ It works well for small arrays, but performance may degrade as the array size increases.
* **Foreach Push**: This approach has some drawbacks:
	+ It requires an explicit loop, which can make the code more verbose and harder to read.
	+ It's slower than the push spread approach due to the iteration overhead.

However, foreach push can still be beneficial in certain situations:

* When working with large arrays or datasets where memory is a concern.
* In cases where readability is more important than performance (e.g., when explaining complex logic).

**Other Considerations**

Other factors that might influence the benchmark results include:

* Array length and size: Larger arrays may favor push spread due to its faster performance.
* JavaScript engine version and optimizations: Different engines or versions might optimize one approach over the other.
* Browser support: Some browsers might have limitations or quirks when using the spread operator.

**Library Usage**

There are no notable libraries used in this benchmark. The `const` keyword is used to declare variables, and the `push` method is a native JavaScript array method.

**Special JS Features or Syntax**

The spread operator (`...`) introduced in ECMAScript 2015 (ES6) allows for concise array concatenation. However, it's not a special feature per se but rather a new syntax that provides a more readable way of achieving the same result as `push`.

**Alternatives**

Some alternatives to these approaches might include:

* Using `Array.prototype.concat()` instead of the spread operator or foreach loop.
* Employing other array append methods, such as `unshift()`, `splice()`, or `reduce()`.
* Using a library like Lodash's `concat` function for more complex concatenation scenarios.

Keep in mind that these alternatives might offer different trade-offs in terms of performance, readability, and memory usage.

Related benchmarks:

push spread vs push foreach (version: 0)

Comparing performance of: push spread vs foreach push

Created: 4 years ago by: Guest

Jump to the latest result

push spread

foreach push

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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