Benchmark: Array concat vs spread operator vs for each push

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 ]
Push
var params = [ "hello", true, 7 ]; var other = [ 1, 2 ]; for (let o of params) { other.push(o); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and the pros and cons of each approach.

**Benchmark Overview**

The benchmark is designed to compare three approaches for concatenating arrays in JavaScript:

1. `Array.prototype.concat()`
2. The new ES6 spread operator (`...`)
3. A manual loop using `push()` method

**Comparison of Approaches**

Here's a brief overview of each approach and their pros and cons:

### 1. `Array.prototype.concat()`

* **Pros:**
	+ Simple and straightforward to implement
	+ Well-documented and widely supported
* **Cons:**
	+ Creates a new array object, which can lead to performance issues if done frequently
	+ May not be as efficient as other approaches

### 2. Spread Operator (`...`)

* **Pros:**
	+ Concise and expressive syntax
	+ Can improve code readability
	+ More efficient than `concat()` for large datasets
* **Cons:**
	+ Requires support for ES6 features (which may not be available in older browsers or environments)
	+ May not work as expected if the spread operator is used with non-array types

### 3. Manual Loop using `push()`

* **Pros:**
	+ No additional library dependencies required
	+ Works with any JavaScript engine and browser, regardless of support for ES6 features
* **Cons:**
	+ Verbose syntax can lead to readability issues
	+ May not be as efficient as the spread operator or `concat()` for large datasets

**Library Usage**

None of the benchmark test cases use a specific library. However, the JavaScript engine and browser used by the test (Chrome 76 on Mac OS X) may utilize various libraries under the hood.

**Special JS Features/Syntax**

The benchmark uses ES6 features such as:

* Spread operator (`...`)
* `let` declaration syntax
* Template literals (`\r\n`) for multiline string concatenation

These features are not universally supported and may require specific JavaScript engines or browsers to execute correctly.

**Alternative Approaches**

Other approaches that could be used for array concatenation include:

* Using the `Array.prototype.reduce()` method
* Utilizing a utility function like Lodash's `concat()`
* Employing a more specialized library or framework-specific solution

However, these alternatives are not being tested in this benchmark.

In summary, the benchmark provides a straightforward comparison of three approaches for array concatenation in JavaScript: `Array.prototype.concat()`, the spread operator (`...`), and a manual loop using `push()`. While each approach has its pros and cons, the spread operator is likely to be the most efficient and concise solution, but may require specific support for ES6 features.

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.100 Safari/537.36

Browser/OS: Chrome 76 on Mac OS X 10.14.4

View result in a separate tab

Test name	Executions per second
Array.prototype.concat	2867788.8 Ops/sec
spread operator	25474494.0 Ops/sec
Push	29785854.0 Ops/sec

Related benchmarks:

Array concat vs spread operator vs for each push (version: 0)

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

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

Created: 5 years ago by: Guest

Jump to the latest result

Array.prototype.concat

spread operator

Push

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):