Benchmark: Array.prototype.concat vs spread operator

HTML Preparation code:

<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.core.js"></script>

Tests:

Array.prototype.concat
var params = [ "hello", true, 7 ]; var other = [ 1, 2 ].concat(params);
spread operator
var params = [ "hello", true, 7 ] var other = [ 1, 2, ...params ]
lodash concat
var params = [ "hello", true, 7 ]; var other = _.concat([ 1, 2 ], params);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
spread operator
lodash concat

Fastest: N/A

Slowest: N/A

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

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Let's break down the provided benchmark and its test cases.

**Overview of the Benchmark**

The benchmark compares three different approaches to concatenate arrays in JavaScript:

1. The traditional `Array.prototype.concat()` method
2. The new ES6 spread operator (`...`)
3. A helper function from the Lodash library, specifically the `_.concat()` function

**Options Compared**

The benchmark is comparing two main options for concatenating arrays:

* Option 1: Using the traditional `Array.prototype.concat()` method
* Option 2: Using the new ES6 spread operator (`...`)

The Lodash version is used as a control group to compare its performance with the two other methods.

**Pros and Cons of Each Approach**

Here are some general pros and cons of each approach:

1. **Traditional `Array.prototype.concat()` method**
	* Pros:
		+ Widely supported by most browsers
		+ Well-known and familiar to many developers
	* Cons:
		+ Can be slower than other methods due to the overhead of creating a new array
2. **New ES6 spread operator (`...`)**
	* Pros:
		+ Faster than traditional `concat()` method due to its native support
		+ More concise and readable syntax
	* Cons:
		+ Not supported by older browsers (e.g., Internet Explorer)
		+ May not be as widely understood or familiar to developers compared to traditional `concat()`
3. **Lodash `.concat()` function**
	* Pros:
		+ Well-tested and optimized for performance
		+ Provides a reliable fallback option in case of browser compatibility issues
	* Cons:
		+ Requires an external library (Lodash) to be included in the test environment

**Library and Syntax Used**

The Lodash library is used as a control group to compare its performance with the two other methods. Specifically, the `_.concat()` function is being tested.

There are no special JavaScript features or syntaxes used beyond what's standard in modern JavaScript development (ES6+).

**Other Alternatives**

If you're looking for alternative approaches to concatenate arrays, here are a few options:

1. Using `Array.prototype.push()`: Instead of concatenating two arrays, you can use the `push()` method to add elements to an array and then return the updated array.
```javascript
var arr = [1, 2];
arr.push(3);
return arr;
```
2. Using `Array.prototype.reduce()`: You can use the `reduce()` method to concatenate two arrays by accumulating the results of each element in one array to create a new array.
```javascript
var arr = [1, 2].concat([3, 4]);
return arr.reduce((a, b) => [...a, b], []);
```
However, these alternatives may have different performance characteristics and trade-offs compared to the three methods being tested in the benchmark.

Related benchmarks:

Array.prototype.concat vs spread operator (version: 2)

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

Comparing performance of: Array.prototype.concat vs spread operator vs lodash concat

Created: 8 years ago by: Registered User

Jump to the latest result

Array.prototype.concat

spread operator

lodash concat

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):