Benchmark: Spread operator vs Array push - 123123KASJDH123

Tests:

Spread operator
var events = new Array(100).fill(256); var promisesArr = []; events.forEach(event => { promisesArr = [ {event: "A", number: event}, {event: "B", number: event*2}, {event: "C", number: event*3}, ...promisesArr ]; });
Push
var events = new Array(100).fill(256); var promisesArr = []; events.forEach(event => { promisesArr.push({event: "A", number: event}); promisesArr.push({event: "B", number: event*2}); promisesArr.push({event: "C", number: event*3}); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread operator
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 break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark compares two approaches for creating an array of objects: using the spread operator (`...`) and the traditional `push()` method. The test is designed to measure which approach is faster on a specific device (Mobile, Android 9) with Chrome Mobile version 76.

**Options Compared**

There are two options being compared:

1. **Spread Operator**: Uses the new ES6 spread operator (`...`) to create an array of objects.
2. **Push**: Uses the traditional `push()` method to add elements to an array.

**Pros and Cons of Each Approach**

**Spread Operator:**

Pros:

* More concise and expressive code
* Can be more efficient in certain situations (e.g., creating a new array with a small number of elements)

Cons:

* May not be supported in older browsers or JavaScript engines
* Can be slower for very large arrays due to the overhead of creating a new array

**Push:**

Pros:

* Widely supported across all browsers and JavaScript engines
* Efficient for appending elements to an existing array

Cons:

* More verbose code
* May incur performance penalties when dealing with large arrays (due to the overhead of concatenating arrays)

**Library Used**

The benchmark uses a custom script that defines the `events` array and the `promisesArr` variable. The script also includes a loop that iterates over the `events` array and adds elements to `promisesArr`. The specific library used is not mentioned, but it's likely a simple JavaScript implementation.

**Special JS Feature or Syntax**

The benchmark uses the spread operator (`...`) which is a new feature introduced in ES6. This means that the test requires a modern JavaScript engine (or a polyfill) to run correctly.

**Other Considerations**

When interpreting the benchmark results, it's essential to consider the following factors:

* Device and browser specifics: The test was run on a Mobile device with Chrome Mobile version 76. Other devices or browsers might yield different results.
* Array size: The test uses an array of 100 elements, which is relatively small. For larger arrays, the push() method may incur performance penalties.
* JavaScript engine: The benchmark requires a modern JavaScript engine (or a polyfill) to run correctly.

**Alternatives**

If you're interested in creating benchmarks for other JavaScript features or libraries, consider using tools like:

* Jest or Mocha for test framework and assertion library
* WebPageTest or Benchmark.js for measuring performance and execution time
* ES6-polyfills or browser-specific polyfills (e.g., V8 for Chrome) to ensure compatibility with older browsers

When creating benchmarks, keep in mind the importance of:

* Isolating variables and dependencies to ensure accurate results
* Using representative inputs and edge cases
* Considering device and browser specifics when interpreting results

Related benchmarks:

Spread operator vs Array push - 123123KASJDH123 (version: 0)

Compare the new ES6 spread operator with the traditional concat() method and push

Comparing performance of: Spread operator vs Push

Created: 6 years ago by: Guest

Jump to the latest result

Spread operator

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):