Benchmark: concat vs spread cb

Script Preparation code:

var params = [ "hello", true, 7 ];

Tests:

Concat
const other = [ 1, 2 ].concat(params);
spread
const other = [ 1, 2, ...params ]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Concat
spread

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:107.0) Gecko/20100101 Firefox/107.0

Browser/OS: Firefox 107 on Windows

View result in a separate tab

Test name	Executions per second
Concat	26256236.0 Ops/sec
spread	33295148.0 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**What is being tested?**

The test compares two ways of concatenating arrays in JavaScript:

1. `concat()`: The traditional method of joining two or more arrays using the `concat()` function.
2. Spread operator (`...`): A newer method of spreading elements from one array into another, introduced in ECMAScript 2015.

**Options compared:**

The two options being compared are:

* Using the `concat()` function to concatenate two arrays.
* Using the spread operator (`...`) to concatenate two arrays.

**Pros and Cons of each approach:**

1. **`concat()`**:
	* Pros:
		+ Widely supported across older browsers and versions.
		+ Can be more readable, especially for those familiar with the `concat()` function.
	* Cons:
		+ Generally slower than the spread operator due to the overhead of creating a new array.
		+ Less memory-efficient, as it creates a new array object.
2. **Spread operator (`...`)**:
	* Pros:
		+ Faster and more memory-efficient than `concat()`, as it avoids creating a new array object.
		+ More concise and readable for those familiar with the spread syntax.
	* Cons:
		+ Less widely supported across older browsers and versions (although this is improving).
		+ May require more time to learn and understand, especially for those unfamiliar with the syntax.

**Library usage:**

The test doesn't appear to use any external libraries beyond the built-in JavaScript `concat()` function. However, it's worth noting that some modern implementations of `concat()` may use a library or internal implementation under the hood (e.g., V8 in Chrome).

**Special JS feature or syntax:**

This benchmark uses the spread operator (`...`), which is a relatively new feature introduced in ECMAScript 2015. While it's widely supported across most modern browsers, its usage might require additional time to learn and understand for those not familiar with this syntax.

**Other alternatives:**

If you need alternative ways of concatenating arrays, consider the following:

1. `Array.prototype.concat()`: This is a static method on the `Array` prototype that can be used in a similar way to the `concat()` function.
2. `Array.prototype.push(...)` and `Array.prototype.shift()`: While not as efficient or readable for large array concatenations, these methods can be used to add elements to an array and then shift existing elements to make room for new ones.

In summary, this benchmark tests two common ways of concatenating arrays in JavaScript: using the traditional `concat()` function versus the newer spread operator syntax. The test highlights the pros and cons of each approach, which can help developers understand performance differences and code readability trade-offs when working with array concatenations.

Related benchmarks:

concat vs spread cb (version: 0)

concat vs spread

Comparing performance of: Concat vs spread

Created: 2 years ago by: Guest

Jump to the latest result

Concat

spread

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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