Benchmark: arr.push(item) && arr vs [...arr, item]

Tests:

arr.push(item) && arr
var a = [1,2]; var b = a.push(3) && a;
[...arr, item]
var a = [1,2]; var b = [...a, 3];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
arr.push(item) && arr
[...arr, item]

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's dive into the world of MeasureThat.net and explore what's being tested in this benchmark.

**Benchmark Definition**

The Benchmark Definition represents two different approaches to appending an item to an array in JavaScript:

1. **`arr.push(item) && arr`**: This approach uses the `push()` method to add an item to the end of the array, followed by a logical AND operation (`&&`) that returns the original array value.
2. **`[...arr, item]`**: This approach uses the spread operator (`...`) to create a new array with the existing elements and then adds a new item to the end of the array.

**Options Compared**

The two approaches are being compared for their performance characteristics, specifically:

* The number of executions per second (ExecutionsPerSecond) on various devices.
* The browser version and platform used in the test.

**Pros and Cons**

1. **`arr.push(item) && arr`**:
	* Pros: This approach is concise and uses built-in JavaScript methods, which can be more efficient.
	* Cons: The logical AND operation (`&&`) may introduce additional overhead due to the need for branching and potential function call overhead.
2. **`[...arr, item]`**:
	* Pros: This approach creates a new array using the spread operator, which can be more predictable in terms of performance.
	* Cons: Creating a new array can be memory-intensive, especially for large datasets.

**Library**

None of the benchmark tests use any external libraries. The code is self-contained and only relies on built-in JavaScript features.

**Special JS Features**

The benchmark tests do not use any special or experimental JavaScript features, such as async/await, generators, or modules (ES6+).

**Other Considerations**

To get accurate results, the following considerations are essential:

* Ensure that the array being tested is large and dense enough to demonstrate performance differences between the two approaches.
* Use a suitable device platform and browser version to represent real-world scenarios.
* Avoid using benchmarking techniques that introduce artificial overhead or skew results.

**Alternatives**

Other alternatives for appending an item to an array in JavaScript include:

1. **Array.prototype splice()**: Splices the element at a specified index, shifting all subsequent elements down by one position. While similar to `push()`, it can be slower due to its mutability.
2. **Array.prototype unshift()**: Adds one or more elements to the beginning of an array. This approach is generally faster than `push()` but may not be suitable for inserting items at arbitrary indices.

Keep in mind that these alternatives are not directly related to the benchmark being tested, which focuses on the performance comparison between the two specific approaches: `arr.push(item) && arr` and `[...arr, item]`.

Related benchmarks:

arr.push(item) && arr vs [...arr, item] (version: 0)

Comparing performance of: arr.push(item) && arr vs [...arr, item]

Created: 5 years ago by: Guest

Jump to the latest result

arr.push(item) && arr

[...arr, item]

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):