Benchmark: push vs new/spread

Script Preparation code:

var using = (new Array(10000)).fill(null).map((e, i) => (i));

Tests:

new/spread
using.reduce((acc, next) => ([...acc, 'a_' + next]), [])
push
using.reduce((acc, next) => { acc.push('a_' + next); return acc; }, [])

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new/spread
push

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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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 is being tested, compared options, their pros and cons, and other considerations.

**Benchmark Definition**

The benchmark is defined by two test cases: "push" and "new/spread". The script preparation code for both tests is the same:
```javascript
var using = (new Array(10000)).fill(null).map((e, i) => (i));
```
This code creates an array of 10,000 elements, where each element is a unique number from 0 to 9,999. This is done using the `map` function and a lambda expression.

The HTML preparation code is empty for both tests, which means that no additional setup or rendering is required before running the benchmark.

**Test Cases**

There are two test cases:

1. "push"
	* Benchmark Definition: `using.reduce((acc, next) => { acc.push('a_' + next); return acc; }, [])`
2. "new/spread"
	* Benchmark Definition: `using.reduce((acc, next) => ([...acc, 'a_' + next]), [])`

**Comparison**

The two test cases compare the performance of using the `push` method versus using the spread operator (`[...]`) to add elements to an array.

**Pros and Cons**

1. **Push Method**
	* Pros:
		+ Simple and straightforward implementation
		+ Can be faster for smaller arrays, as it avoids the overhead of creating a new array
	* Cons:
		+ For larger arrays, it can lead to slower performance due to the need to allocate new memory on each push operation
2. **Spread Operator**
	* Pros:
		+ More efficient for large arrays, as it avoids the need for repeated `push` operations
		+ Can be faster in some browsers and engines, such as V8 (the JavaScript engine used by Chrome)
	* Cons:
		+ Requires a more complex implementation, which can lead to slower performance for smaller arrays

**Library**

There is no explicit library mentioned in the benchmark definition. However, it's worth noting that the `map` function is part of the ECMAScript standard, and the spread operator (`[...]`) was introduced in ECMAScript 2015 (ES6).

**Special JS Feature or Syntax**

The use of arrow functions (`(e, i) => (i)`) and template literals (`'a_' + next`) are examples of newer JavaScript features that were introduced in ECMAScript 2015. These features can affect the performance and syntax of the code.

**Other Considerations**

When writing benchmarks, it's essential to consider factors like:

* Input size: Larger inputs can lead to different performance characteristics for each test case.
* Browser and engine variations: Different browsers and engines may have varying degrees of support for certain features or optimizations.
* Hardware and platform differences: The performance of the benchmark can vary depending on the hardware, CPU architecture, and operating system.

**Alternatives**

Other alternatives for benchmarking JavaScript performance include:

* Microbenchmark libraries like ` Benchmark.js` or `Benchmark.chai`
* Benchmarking frameworks like ` Jest` or `Mocha`
* Browser-specific benchmarks, such as those provided by Google's Chrome DevTools

Keep in mind that different benchmarking tools and approaches may provide different results or emphasis on specific aspects of performance.

Related benchmarks:

push vs new/spread (version: 0)

Comparing performance of: new/spread vs push

Created: 3 years ago by: Guest

Jump to the latest result

new/spread

push

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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