Benchmark: My first test - MeasureThat.net

Script Preparation code:

var arr1 = ["a", "b", "c", "d"];

Tests:

SPREAD
var result = [...["x", "y", "z"], ...arr1];
UNSHIFT
var result = arr1.unshift("x", "y", "z");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
SPREAD
UNSHIFT

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what's being tested, compared options, pros and cons, library usage, special JavaScript features or syntax, and other considerations.

**Benchmark Definition**

The benchmark is defined as a simple "speed test" with two individual test cases: `SPREAD` and `UNSHIFT`.

**Script Preparation Code**

The script preparation code is the same for both test cases:
```
var arr1 = [\"a\", \"b\", \"c\", \"d\];
```
This creates an array `arr1` containing four string elements.

**Html Preparation Code**

The html preparation code is null, which means that no HTML content is prepared before running the benchmark. This might be useful for comparing the performance of different JavaScript engines or browsers in a sandboxed environment.

**Test Cases**

There are two test cases:

### SPREAD

Benchmark Definition:
```
var result = [...[\"x\", \"y\", \"z\"], ...arr1];
```
This test case creates an array `result` by spreading the elements of another array (`arr1`) into a new array (`[[\"x\", \"y\", \"z\"]]`). The spread operator is used to concatenate the two arrays.

### UNSHIFT

Benchmark Definition:
```
var result = arr1.unshift(\"x\", \"y\", \"z\");
```
This test case creates an array `result` by unshifting three new elements (`"x"`, `"y"`, and `"z"`) onto the beginning of the original array `arr1`.

**Options Compared**

The two test cases compare two different approaches to manipulate arrays in JavaScript:

*   **SPREAD**: uses the spread operator (`...`) to concatenate arrays.
*   **UNSHIFT**: modifies the original array by unshifting new elements onto its beginning.

**Pros and Cons**

### SPREAD

Pros:

*   More concise and readable code
*   Less memory allocation, as only one new array is created

Cons:

*   May be slower due to the overhead of creating a new array
*   Requires JavaScript engines that support the spread operator (most modern browsers do)

### UNSHIFT

Pros:

*   Can be faster for small arrays, since it modifies the original array in-place
*   Does not require creating a new array

Cons:

*   Less concise and readable code
*   Modifies the original array, which can be unexpected behavior
*   Requires JavaScript engines that support `unshift` (most modern browsers do)

**Library Usage**

There is no explicit library usage mentioned in this benchmark. However, some JavaScript engines might use additional libraries or frameworks for their implementation.

**Special JavaScript Features or Syntax**

The spread operator (`...`) and the `unshift` method are special features of JavaScript that allow for concise array manipulation. These features were introduced in ECMAScript 2015 (ES6) as part of the new standard.

Other Considerations

*   This benchmark might be useful for evaluating the performance of different JavaScript engines or browsers, especially when it comes to array manipulation.
*   The use of `var` declarations and no object-oriented programming syntax suggests that this benchmark is intended to test the performance of basic JavaScript operations, rather than more complex scenarios.

**Alternatives**

There are other alternatives for testing JavaScript performance:

*   [BenchmarkDotNet](https://github.com/dotnet/benchmarkdotnet): a .NET library specifically designed for measuring performance in various programming languages, including JavaScript.
*   [js-bench](https://github.com/krismays/js-bench): a JavaScript benchmarking framework that provides a simple way to write and run benchmarks.
*   [Benchmark.js](https://benchmarkjs.com/): a popular benchmarking library for JavaScript that allows you to create and run benchmarks easily.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/106.0.0.0 Safari/537.36

Browser/OS: Chrome 106 on Windows

View result in a separate tab

Test name	Executions per second
SPREAD	8856003.0 Ops/sec
UNSHIFT	7903.5 Ops/sec

Related benchmarks:

My first test (version: 0)

speed test

Comparing performance of: SPREAD vs UNSHIFT

Created: 2 years ago by: Guest

Jump to the latest result

SPREAD

UNSHIFT

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):