Benchmark: Add new element to array (preparation): push vs destructuring vs bracket access

Script Preparation code:

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

Tests:

spread operator
var other = [ ...params, 'new' ]
Push
params.push('new');
bracket access
params[ params.length ] = 'new';

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread operator
Push
bracket access

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

I'll break down the benchmark test case and explain what's being tested.

**Benchmark Test Case:**

The test case measures the performance of three different ways to add an element to an array in JavaScript:

1. **Push**: Using the `push()` method, which adds a new element at the end of the array.
2. **Destructuring**: Using the spread operator (`...`) to create a new array with the original elements and the new one added.
3. **Bracket access**: Accessing an index that doesn't exist in the array using square brackets `[]`.

**Options Compared:**

The test case compares the performance of these three approaches:

* **Pros and Cons:**
	+ Push:
		- Pros: Simple, widely supported, and efficient for adding a single element.
		- Cons: Can be slower than other methods for large arrays due to the need to resize the array.
	+ Destructuring (Spread Operator):
		- Pros: Efficient, flexible, and can add multiple elements at once. However, it may incur additional overhead due to stringification of the spread operator arguments.
		- Cons: May not be supported by older browsers or environments that don't understand the spread operator syntax.
	+ Bracket Access:
		- Pros: Fast, but requires knowledge of array indices and can lead to errors if not used correctly.
		- Cons: May incur additional overhead due to index calculations, and is less intuitive than other methods.

**Library Used:**

None explicitly mentioned. However, the use of `params` suggests that some external data or configuration is being passed around, but no specific library is required for this benchmark.

**Special JS Features/Syntax:**

The test case uses the spread operator (`...`) and bracket access to add an element to the array. These features are relatively modern and may not be supported by older browsers or environments that don't understand these syntaxes.

**Other Considerations:**

* The benchmark assumes that the original array is not modified elsewhere in the script, ensuring that the results only depend on the specific way of adding the new element.
* The test case uses a single-element array with a fixed length (`params.length`), which simplifies the comparison and reduces overhead.

**Alternatives:**

If you need to measure performance for other ways of adding elements to an array, consider testing:

* `concat()`: Adding an array using `array.concat(newArray)`.
* `set()`: Using `set()` method (if supported by the browser or environment).
* Other array methods like `unshift()`, `splice()`, or using a library-specific solution.

Keep in mind that performance differences may vary depending on the specific use case, data size, and JavaScript engine being used.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/106.0.0.0 Safari/537.36

Browser/OS: Chrome 106 on Windows

View result in a separate tab

Test name	Executions per second
spread operator	9067500.0 Ops/sec
Push	11127881.0 Ops/sec
bracket access	5793709.5 Ops/sec

Related benchmarks:

Add new element to array (preparation): push vs destructuring vs bracket access (version: 0)

Comparing performance of: spread operator vs Push vs bracket access

Created: 2 years ago by: Guest

Jump to the latest result

spread operator

Push

bracket access

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):