Benchmark: concat or spread ops

Script Preparation code:

var list = [...Array(1000).keys()].map((index) => {return {id: index, name: `PRODUCT_${index}`}});
var newItems = [{id: 50, name: 'CUST_50'}, {id: 412, name: 'CUST_412'}];

Tests:

concat
var x = list.concat(newItems);
spread
var y = [...list, ...newItems];

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:

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 benchmark and its options.

**Benchmark Overview**

The benchmark, named "concat or spread ops," tests the performance of two different approaches to concatenate arrays in JavaScript: using the `concat()` method and using the spread operator (`...`).

**Script Preparation Code**

The script preparation code creates two arrays:

1. `list`: An array of 1000 objects, each with an `id` and a `name` property.
2. `newItems`: A small array of two objects.

These arrays are created using JavaScript's array creation methods.

**Options Being Compared**

There are two options being compared in this benchmark:

1. **`concat()` method**: The `concat()` method is used to concatenate two or more arrays. It returns a new array containing all elements from the original arrays.
2. **Spread operator (`...`)**: The spread operator is used to create a new array by copying elements from one or more source arrays.

**Pros and Cons of Each Approach**

1. **`concat()` method**:
	* Pros:
		+ Widely supported across JavaScript implementations.
		+ Can be used with any type of data, not just arrays.
	* Cons:
		+ Creates a new array, which can lead to increased memory usage.
		+ Can be slower than the spread operator for large datasets.
2. **Spread operator (`...`)**:
	* Pros:
		+ More efficient and faster than `concat()` for large datasets.
		+ Reduces memory allocation by reusing existing arrays.
	* Cons:
		+ Only available in modern JavaScript implementations (ECMAScript 2015+).
		+ Can be slower in older browsers or environments that don't support it.

**Library Usage**

There is no library being used in this benchmark. The script preparation code only uses built-in JavaScript array creation methods.

**Special JS Feature/Syntax**

The spread operator (`...`) is a special feature of modern JavaScript, introduced in ECMAScript 2015. It's not supported in older browsers or environments that don't implement it. However, the benchmark doesn't use any special JavaScript features or syntax other than the spread operator.

**Other Alternatives**

For large datasets, other approaches to concatenate arrays could be considered:

1. **Using a library**: Libraries like Lodash provide optimized array concatenation functions.
2. **Iterative approach**: Looping over one of the arrays and appending elements to another array.
3. **Buffer-based approach**: Using a buffer to store concatenated data, which can improve performance for large datasets.

However, these alternatives are not tested in this benchmark, and their performance may vary depending on specific use cases and environments.

Related benchmarks:

concat or spread ops (version: 0)

Comparing performance of: concat vs spread

Created: 8 years ago by: Registered User

Jump to the latest result

concat

spread

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):