Benchmark: Array concat vs spread operator vs push single element

Tests:

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

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

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36

Browser/OS: Chrome 105 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Array.prototype.concat	16629059.0 Ops/sec
spread operator	50305124.0 Ops/sec
Push	82594208.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what's being tested, compared, and their pros and cons.

**What is tested?**

The benchmark compares three ways to concatenate or append an element to an array in JavaScript:

1. **Array.prototype.concat()**: A traditional method that creates a new array by copying the existing array and adding the new element.
2. **Spread operator (new ES6 syntax)**: A shorthand way to create a new array by spreading the elements of an existing array and adding a new element.
3. **Push() method**: An array method that modifies the original array in place, appending a new element.

**What options are compared?**

The benchmark is designed to compare these three approaches for their performance. The order of comparison might vary depending on the implementation, but typically, it would be:

1. Array.prototype.concat()
2. Push() method
3. Spread operator

**Pros and cons of each approach:**

* **Array.prototype.concat():**
	+ Pros: Generally considered a safe and reliable method.
	+ Cons: Creates a new array, which can lead to performance issues if the original array is large.
	+ This approach is often used in legacy code or when working with older browsers that don't support modern ES6 features.
* **Push() method:**
	+ Pros: Modifies the original array in place, reducing memory allocation and deallocation overhead.
	+ Cons: Can be slower than other approaches for small arrays due to the need to check if the array is full before adding an element.
	+ This approach is often used when working with large datasets or optimizing performance-critical code.
* **Spread operator (new ES6 syntax):**
	+ Pros: Concise and expressive syntax, allowing for more readable code.
	+ Cons: May incur overhead due to the creation of a new array object.

**Library and its purpose**

There are no libraries mentioned in the provided JSON. However, it's worth noting that some JavaScript engines or browsers might provide additional optimizations or features for array operations.

**Special JS feature or syntax**

The spread operator (new ES6 syntax) is a modern JavaScript feature introduced in ECMAScript 2018. It allows for more concise and expressive code when working with arrays, objects, or other collections.

**Other alternatives**

In addition to the three approaches mentioned above, there are other methods that can be used to concatenate or append an element to an array, such as:

* **Array.prototype.push.apply()**: A variant of the Push() method that takes multiple arguments and applies them to the end of the array.
* **Array.prototype.unshift()**: A method that adds elements to the beginning of the array.

However, these alternatives might not be included in the benchmark due to performance or syntax considerations.

In summary, the benchmark provides a comparison of three approaches for concatenating or appending an element to an array in JavaScript: Array.prototype.concat(), Push() method, and spread operator (new ES6 syntax). Each approach has its pros and cons, and understanding these differences can help developers make informed decisions about which method to use in their code.

Related benchmarks:

Array concat vs spread operator vs push single element (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 2 months ago):