Benchmark: arr unshift vs double reverse and push1

Script Preparation code:

var arr = [42];

Tests:

unshift
arr.unshift(1);
reverse push reverse
arr.reverse(); arr.push(1); arr.reverse();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
unshift
reverse push reverse

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 dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**What is tested?**

The provided benchmark measures the performance difference between two approaches:

1. `arr.unshift(1);`
2. `arr.reverse(); arr.push(1); arr.reverse();`

These two approaches are used to add a single element (the number 1) to an array (`arr`). The goal is to determine which approach is faster.

**Options compared**

The benchmark compares two options:

* **`unshift()`**: A method that adds one or more elements to the beginning of an array.
* **`reverse()` + `push()` + `reverse()`**: A chain of methods that first reverses the order of the array, pushes a new element to the end, and then reverses the array back to its original order.

**Pros and cons of each approach**

1. **`unshift()`**:
	* Pros: Efficient insertion at the beginning of the array, as it only requires updating internal pointers.
	* Cons: May not be suitable for large arrays, as it can lead to a lot of memory allocation and copying.
2. **`reverse()` + `push()` + `reverse()`**:
	* Pros: Suitable for large arrays, as it doesn't require updating internal pointers at the beginning of the array.
	* Cons: Less efficient than `unshift()`, as it involves more operations (reversing and pushing).

**Library usage**

None of the provided benchmark definitions use any libraries. However, MeasureThat.net itself is a web-based platform that uses JavaScript to execute benchmarks.

**Special JS features or syntax**

There are no special features or syntax mentioned in the benchmark definition. The focus is on comparing two simple array operations.

**Other alternatives**

If you wanted to test different approaches for adding an element to an array, here are some alternative methods:

* Using `concat()` to create a new array with the added element: `arr = arr.concat([1]);`
* Using `splice()` to insert the element at a specific index: `arr.splice(0, 0, 1);`
* Using a custom implementation that avoids built-in array methods (not recommended for performance-critical code)

Keep in mind that these alternatives might not be as efficient or concise as the original approaches used in the benchmark.

I hope this explanation helps you understand what's being tested in the MeasureThat.net benchmark!

Related benchmarks:

arr unshift vs double reverse and push1 (version: 0)

Comparing performance of: unshift vs reverse push reverse

Created: 5 years ago by: Guest

Jump to the latest result

unshift

reverse push reverse

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):