Benchmark: unshift - MeasureThat.net

Script Preparation code:

a = [1,2,3,4,5]

Tests:

[123].concat(a)
[123].concat(a)
splice
a.splice(0,0,123)
reverse.push.reverse
a.reverse().push(123) a.reverse()
unshift
a.unshift(123)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
[123].concat(a)
splice
reverse.push.reverse
unshift

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.96 Safari/537.36

Browser/OS: Chrome 88 on Linux

View result in a separate tab

Test name	Executions per second
[123].concat(a)	989283.5 Ops/sec
splice	1662.8 Ops/sec
reverse.push.reverse	14838.7 Ops/sec
unshift	35529.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON benchmark definitions and explain what's being tested, compared, and their pros and cons.

**Benchmark Definitions**

The provided benchmark definition is a JSON object that defines three microbenchmarks:

1. `[123].concat(a)`
2. `a.splice(0, 0, 123)`
3. `a.reverse().push(123) a.reverse()`
4. `a.unshift(123)`

These benchmarks test the performance of different array operations in JavaScript.

**Options being compared**

The options being compared are:

* **Concatenation**: `[123].concat(a)` vs `a.splice(0, 0, 123)`
	+ Pros:
		- Concatenation is a more traditional and widely supported approach.
		- It allows for easier addition of new elements to the array.
	+ Cons:
		- Can be slower due to creating a new array object.
* **Unshifting**: `a.unshift(123)`
	+ Pros:
		- Unshifting is faster because it only updates the internal pointer of the array.
		- It's also more memory-efficient since no new array object is created.
	+ Cons:
		- Not supported in all browsers (e.g., Internet Explorer).
* **Splicing**: `a.splice(0, 0, 123)`
	+ Pros:
		- Splicing can be faster than concatenation due to its more optimized implementation under the hood.
	+ Cons:
		- Can be slower for very large arrays since it has to update all elements after the insertion point.

**Other considerations**

* **Array reversal**: `a.reverse().push(123) a.reverse()`
	+ This benchmark is testing both the performance of reversing an array and pushing an element onto it. The `reverse()` method reverses the entire array, which can be slower than other methods.
* **Loop optimizations**
	+ It's worth noting that loop optimizations in JavaScript are generally not as effective as they are in languages like C++ or Java.

**Library usage**

There is no specific library used in these benchmarks. However, it's common for benchmarking to use libraries like `Benchmark` or `micro-benchmark`, which provide a simple way to write and run benchmarks.

**Special JS features**

None of the provided benchmarks use special JavaScript features like ES6 modules, async/await, or generators. If they did, we would need to consider how those features might affect the benchmarking process.

**Alternatives**

Other alternatives for measuring performance in JavaScript include:

* **V8 Profiler**: Google's V8 engine provides a built-in profiler that allows you to analyze the execution time of individual functions and methods.
* **Chrome DevTools**: Chrome's DevTools provide a Performance Tab where you can run benchmarks and view profiling data.
* **Benchmarking libraries like Benchmark** or **micro-benchmark**: These libraries allow you to write simple, repeatable benchmarks for your JavaScript code.

These alternatives might offer more detailed insights into performance characteristics than the `MeasureThat.net` benchmarking tool.

Related benchmarks:

unshift (version: 0)

Comparing performance of: [123].concat(a) vs splice vs reverse.push.reverse vs unshift

Created: 3 years ago by: Guest

Jump to the latest result

[123].concat(a)

splice

reverse.push.reverse

unshift

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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