Benchmark: string to array, push vs concat

Tests:

push
'0'.repeat(400).split('').reduce((a, b) => {a.push(b, ''); return a;}, [])
concat
'0'.repeat(400).split('').reduce((a, b) => a.concat(b, ''), [])

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
push
concat

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 28 days ago)

User agent: Mozilla/5.0 (Android 15; Mobile; rv:137.0) Gecko/137.0 Firefox/137.0

Browser/OS: Firefox Mobile 137 on Android

View result in a separate tab

Test name	Executions per second
push	120988.4 Ops/sec
concat	6512.4 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 7 months ago):

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**
The benchmark definition represents the JavaScript code to be executed in a microbenchmarking environment. In this case, there are two test cases:

1. `push`: This test case uses the `push` method to add elements to an array. The benchmark definition is:
```javascript
'0'.repeat(400).split('').reduce((a, b) => {a.push(b, ''); return a;}, [])
```
This code creates an array of 400 zeros (using `'0'.repeat(400)`), splits it into individual elements using `split('')`, and then reduces the resulting array to create a new array where each element is a single zero (`b`).

2. `concat`: This test case uses the `concat` method to add elements to an array. The benchmark definition is:
```javascript
'0'.repeat(400).split('').reduce((a, b) => a.concat(b, ''), [])
```
This code creates an array of 400 zeros (using `'0'.repeat(400)`), splits it into individual elements using `split('')`, and then reduces the resulting array to create a new array where each element is a single zero (`b`) concatenated with an empty string (`''`).

**Options Compared**
The two test cases compare the performance of using the `push` method versus the `concat` method when adding multiple elements to an array.

**Pros and Cons**

* **Push Method**:
	+ Pros: Generally faster and more efficient, as it avoids creating intermediate arrays.
	+ Cons: Can be less readable and more error-prone due to its side-effecting nature (modifying the original array).
* **Concat Method**:
	+ Pros: More readable and easier to reason about, as it creates a new array with the concatenated elements.
	+ Cons: Generally slower and more memory-intensive, especially for large arrays.

In general, using `push` is preferred when performance is critical, but readability and maintainability are also important. In this case, both methods have their trade-offs.

**Library**
There is no library explicitly mentioned in the benchmark definition or test cases. However, some JavaScript implementations might provide additional optimizations or built-in functions for array manipulation (e.g., `Array.prototype.push()` and `Array.prototype.concat()`).

**Special JS Feature or Syntax**
None of the provided test cases rely on any special JavaScript features or syntax that would affect their execution.

**Other Alternatives**

If you want to explore alternative approaches, consider:

1. Using `Array.prototype.unshift()`: This method can be more efficient than `push` for small arrays, but its performance degrades as the array size increases.
2. Implementing a custom array buffer or data structure: For specific use cases, building an optimized data structure from scratch might provide better performance, but it requires significant expertise and effort.
3. Using specialized libraries or frameworks (e.g., WebAssembly, SIMD instructions): Depending on your use case, using optimized libraries or frameworks can significantly improve performance.

Keep in mind that each approach has its trade-offs, and the best choice depends on your specific requirements, target audience, and performance constraints.

Related benchmarks:

string to array, push vs concat (version: 0)

Comparing performance of: push vs concat

Created: one year ago by: Guest

Jump to the latest result

push

concat

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 7 months ago):