Benchmark: JS concat vs spread operator

Tests:

Array concat
const params = [ "hello", true, 7 ]; [1, 2].concat(params)
spread operator
const params = [ "hello", true, 7 ]; [1, 2, ...params]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array concat
spread operator

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is defined in two parts:

1. **Benchmark Name**: "JS concat vs spread operator" - This describes the main objective of the benchmark, which is to compare the performance of two different methods for concatenating arrays: the traditional `concat()` method and the new ES6 spread operator (`...`).
2. **Script Preparation Code** and **Html Preparation Code**: These fields are empty, indicating that no additional setup or configuration is required for the benchmark.

**Individual Test Cases**

There are only two test cases:

1. **Array concat**: This test case uses the traditional `concat()` method to concatenate an array of strings (`"hello"`), a boolean value (`true`), and an integer value (`7`) with another existing array `[1, 2]`.
2. **Spread operator**: This test case uses the new ES6 spread operator (`...`) to achieve the same concatenation as in the previous test case.

**Pros and Cons of Different Approaches**

Here's a brief analysis of the two approaches:

* **Traditional `concat()` method**:
	+ Pros: Widely supported, easy to understand, and works well for small arrays.
	+ Cons: Can lead to performance issues when dealing with large arrays or repeated concatenations.
* **ES6 spread operator (`...`)**:
	+ Pros: More concise, efficient, and flexible than traditional `concat()` method.
	+ Cons: May not be supported in older browsers, and its behavior can be unexpected if not used carefully.

**Library Usage**

There is no explicit library usage mentioned in the benchmark definition or test cases. However, some JavaScript engines (like Google's V8) have implemented various optimizations and features that might affect the benchmark results. Keep in mind that these are implementation details and may not be relevant to your specific use case.

**Special JS Features/Syntax**

There is no mention of special JavaScript features or syntax in the provided code snippets. However, it's worth noting that some JavaScript engines (like V8) have introduced new features like `const` expressions, which can affect performance.

**Other Alternatives**

If you're looking for alternative methods to concatenate arrays in JavaScript, consider the following:

* Using the `push()` method: `arr.push(...params)`
* Using the `unshift()` method: `[...params].unshift(1, 2, ...arr)`

Keep in mind that these alternatives may have different performance characteristics compared to traditional `concat()` or spread operator methods.

The benchmark results provided show that the ES6 spread operator (`...`) performs better than the traditional `concat()` method on this specific test case. This is likely due to the efficiency and conciseness of the spread operator, which allows the JavaScript engine to optimize away unnecessary overhead.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Linux; Android 10; MAR-LX1A) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.41 Mobile Safari/537.36 (Ecosia [email protected])

Browser/OS: Chrome Mobile 101 on Android

View result in a separate tab

Test name	Executions per second
Array concat	2172428.5 Ops/sec
spread operator	10391807.0 Ops/sec

Related benchmarks:

JS concat vs spread operator (version: 0)

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

Comparing performance of: Array concat vs spread operator

Created: 5 years ago by: Guest

Jump to the latest result

Array concat

spread operator

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):