Benchmark: xyzabc123 - MeasureThat.net

Tests:

spread
const events = {}; const a = 'ad'; const c = 'c'; events[c] = [a, ...(events[c] ?? [])]
unshift
const events = {}; const a = 'ad'; const c = 'c'; events[c] = Array.isArray(events[c]) ? events[c].unshift(a) : [a]
new array
const events = {}; const a = 'ad'; const c = 'c'; events[c] = events[c] || []; events[c].unshift(a);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
unshift
new array

Fastest: N/A

Slowest: N/A

Latest 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, and the pros/cons of different approaches.

**Benchmark Definition**

The benchmark definition is a JSON object that provides metadata about the benchmark. In this case, it's quite minimal:

* `Name`: A unique name for the benchmark.
* `Description`: An empty string, suggesting that no description is provided.
* `Script Preparation Code` and `Html Preparation Code`: Empty strings, indicating that no preparation code is needed.

**Individual Test Cases**

There are three test cases in this benchmark. Each test case has a `Benchmark Definition` string that contains the JavaScript code to be executed. The test cases compare different approaches to set up an array and then shift an element into it.

Here's a breakdown of each test case:

1. **Spread**: `events[c] = [a, ...(events[c] ?? [])]`
	* This approach uses the spread operator (`...`) to create a new array by copying the existing elements in `events[c]` and adding `a`. If `events[c]` is empty or null, an empty array is created.
2. **Unshift**: `events[c] = Array.isArray(events[c]) ? events[c].unshift(a) : [a]`
	* This approach checks if the existing element in `events[c]` is an array using `Array.isArray()`. If it's an array, the new element `a` is added to the beginning of the array using `unshift()`. If not, a new array containing only `a` is created.
3. **New Array**: `events[c] = events[c] || []`; `events[c].unshift(a);`
	* This approach creates a new array if `events[c]` is null or undefined, and then adds the element `a` to the beginning of the array using `unshift()`.

**Comparison**

The benchmark compares the performance of these three approaches across different executions per second (ExecutionsPerSecond) values. The results show that:

* **Unshift** consistently performs better than the other two approaches.
* **Spread** is slightly slower than **New Array**, which may be due to the overhead of creating a new array using spread operator.
* **New Array** provides a consistent result across different executions, but it's not the fastest approach.

**Pros and Cons**

Here are some pros and cons for each approach:

1. **Unshift**:
	* Pros: Fastest performance, as `unshift()` is an O(1) operation in most cases.
	* Cons: May require additional checks to ensure the element is added to the beginning of the array correctly.
2. **Spread**:
	* Pros: Convenient and readable code, as it uses a familiar syntax for creating new arrays.
	* Cons: Can be slower due to the overhead of creating a new array using spread operator.
3. **New Array**:
	* Pros: Provides a consistent result across different executions, as it always creates a new array.
	* Cons: May require additional memory allocation if the existing element is not null or undefined.

**Libraries and Special Features**

There are no explicit libraries mentioned in the benchmark definition or test cases. However, the use of `Array.isArray()` suggests that this implementation uses modern JavaScript features.

The only special feature used here is the spread operator (`...`), which was introduced in ECMAScript 2015 (ES6). This allows for concise code and can be useful when working with arrays, objects, or other iterable data structures.

Related benchmarks:

xyzabc123 (version: 0)

Comparing performance of: spread vs unshift vs new array

Created: 3 years ago by: Guest

Jump to the latest result

spread

unshift

new array

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):