Benchmark: Array deconstruction vs Array push 2

Tests:

Array push
let commentsByPostId = {} const maxInterations = 100000 for (let i = 0; i < maxInterations; i++){ const postId = Math.floor(Math.random() * maxInterations).toString() const comments = commentsByPostId[postId] ?? [] comments.push({ id: i, content: `Test - ${i}` }) commentsByPostId[postId] = comments }
Array deconstruction
let commentsByPostId = {} const maxInterations = 100000 for (let i = 0; i < maxInterations; i++){ const postId = Math.floor(Math.random() * maxInterations).toString() commentsByPostId[postId] = [ ...commentsByPostId[postId] ?? [], ...[{ id: i, content: `Test - ${i}` }] ] }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array push
Array deconstruction

Fastest: N/A

Slowest: N/A

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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 JavaScript microbenchmarks on MeasureThat.net.

**What is being tested?**

MeasureThat.net is testing two different approaches for adding elements to an array in JavaScript:

1. **Array push**: This approach uses the `push()` method to add one or more elements to the end of an array.
2. **Array deconstruction**: This approach uses the spread operator (`...`) and destructuring assignment syntax (e.g., `...commentsByPostId[postId] ?? []` ) to create a new array with the original elements and the newly added ones.

**Options being compared**

The two options are being compared in terms of their execution time, which is measured by the number of executions per second (ExecutionsPerSecond).

**Pros and cons of each approach:**

1. **Array push**
	* Pros:
		+ Widely supported by most JavaScript engines.
		+ Easy to understand and implement.
	* Cons:
		+ Can be slower than array deconstruction for large arrays, since it involves a function call.
2. **Array deconstruction**
	* Pros:
		+ Can be faster than array push for large arrays, as it avoids the overhead of a function call.
		+ More concise and expressive syntax.
	* Cons:
		+ May not be supported by older JavaScript engines or environments that don't understand the spread operator.

**Library**

In both benchmark definitions, no specific library is used. The code only relies on built-in JavaScript features.

**Special JS feature/syntax**

In this benchmark, we see the use of:

1. **Spread operator (`...`)**: A feature introduced in ECMAScript 2015 (ES6) that allows spreading arrays or objects into new ones.
2. **Destructuring assignment**: A feature introduced in ECMAScript 2015 (ES6) that allows extracting values from an array or object.

**Other alternatives**

If you want to explore other approaches, you can consider:

1. **Array.prototype.concat()**: This method concatenates two arrays and returns a new array. It's less efficient than pushing elements directly onto the original array.
2. **Array.prototype.splice()**: This method modifies an array by adding or removing elements at a specified index. It's not typically used for simple addition of elements to the end of an array.

Keep in mind that these alternatives may have different performance characteristics and are often less efficient than using `push()` or array deconstruction.

Related benchmarks:

Array deconstruction vs Array push 2 (version: 0)

Comparing performance of: Array push vs Array deconstruction

Created: 2 years ago by: Guest

Jump to the latest result

Array push

Array deconstruction

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):