Benchmark: Reduce using spread and push and param reassignment

Tests:

Spread
const foo = []; for (let i = 0; i < 10000; i++) { foo.push(i); } const bar = foo.reduce((acc, value) => { if (acc % 5) { return [...acc, value]; } return acc; });
Push
const foo = []; for (let i = 0; i < 10000; i++) { foo.push(i); } const bar = foo.reduce((acc, value) => { const array = acc; if (acc % 5) { array.push(value); } return array; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread
Push

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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.

**What is being tested?**

The provided JSON benchmark represents two test cases for measuring the performance of reducing an array using different approaches. The test cases compare the use of the spread operator (`...`) with pushing elements onto the accumulator array (`acc`).

In each test case, a large array `foo` is created by pushing 10,000 integers from 0 to 9,999 onto it using a `for` loop. Then, the `reduce()` method is used to reduce the array into a single value.

The first test case uses the spread operator (`...`) to create a new array when `acc % 5` is true. The second test case pushes elements onto the accumulator array `array` instead of creating a new one using the spread operator.

**Options compared:**

There are two main approaches being compared:

1. **Spread Operator (```...```)**: This approach creates a new array when `acc % 5` is true, which involves copying the existing elements from `acc` into a new array.
2. **Pushing onto accumulator array (```array.push(value)``**) : In this approach, elements are pushed onto the accumulator array `array` without creating a new one.

**Pros and Cons:**

1. **Spread Operator (`...`)**
	* Pros:
		+ Creates a new array when necessary, avoiding potential side effects on the original array.
		+ Can be more readable and concise for some use cases.
	* Cons:
		+ May incur additional overhead due to creating a new array.
2. **Pushing onto accumulator array (`array.push(value)` )**
	* Pros:
		+ Typically has lower overhead since elements are pushed onto the existing array, without creating a new one.
	* Cons:
		+ Can be less readable and more prone to side effects if not handled carefully.

**Library and purpose:**

There is no explicit library mentioned in the provided benchmark. However, it's worth noting that `reduce()` and array methods like `push()` are built-in JavaScript methods.

**Special JS feature or syntax:**

The use of template literals (`\r\n`) with newline characters (`\n`) is a notable aspect of this benchmark. Template literals allow you to embed expressions inside string literals, which can make code more readable and concise.

However, it's worth noting that the test cases are quite simple and don't rely on any advanced JavaScript features or syntax.

**Other alternatives:**

If you're interested in exploring alternative approaches for reducing arrays, here are a few options:

* Using `Array.prototype.map()` instead of `reduce()`, which would create a new array with transformed elements.
* Implementing your own custom reduction algorithm using loops and conditional statements.
* Utilizing libraries like Lodash or Ramda, which provide more functional programming-friendly alternatives to built-in JavaScript methods.

Keep in mind that the performance benefits of these alternative approaches may vary depending on the specific use case and requirements.

Related benchmarks:

Reduce using spread and push and param reassignment (version: 0)

Comparing performance of: Spread vs Push

Created: 6 years ago by: Guest

Jump to the latest result

Spread

Push

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):