Benchmark: filter and unshift

Script Preparation code:

var arr = [{
    name: "home",
    url: "/"
}, {
    name: "projects",
    url: "/projects"
}];

Tests:

unshift
var newArr = arr.unshift({ name: 'home', url: '/', }) console.log(newArr)
filter
var newArr = arr.filter((el)=>el !== { name: 'home', url: '/', }) console.log(newArr)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
unshift
filter

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Linux; Android 10; RMX2063) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.210 Mobile Safari/537.36

Browser/OS: Chrome Mobile 90 on Android

View result in a separate tab

Test name	Executions per second
unshift	9212.1 Ops/sec
filter	361.1 Ops/sec

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

LLMs can make mistakes. Check important info.

**What is being tested?**

The provided benchmark measures the performance of two JavaScript operations: `unshift` and `filter`. The benchmark tests how quickly these operations can be executed on a sample array.

**Options compared:**

Two approaches are compared:

1. **Array.prototype.unshift**: This method adds an element to the beginning of an array.
2. **Array.prototype.filter**: This method creates a new array with all elements that pass the test implemented by the provided function.

**Pros and Cons of each approach:**

* **Array.prototype.unshift**:
	+ Pros:
		- Can be faster for small arrays since it only requires a single iteration over the existing elements.
		- Can be more efficient when working with sparse arrays or arrays that have few elements.
	+ Cons:
		- Requires allocating new memory to create a new array, which can lead to performance issues with large arrays.
		- May not be suitable for use cases where the array needs to be modified in place (e.g., modifying the original array).
* **Array.prototype.filter**:
	+ Pros:
		- Does not require allocating new memory, making it more suitable for large arrays.
		- Allows the original array to remain unchanged, which can be beneficial when working with large datasets or sensitive data.
	+ Cons:
		- May require multiple iterations over the existing elements, leading to higher overhead.
		- Can lead to slower performance for small arrays due to the additional iteration.

**Library and purpose:**

There is no explicit library mentioned in the provided benchmark definition. However, it's worth noting that both `unshift` and `filter` are built-in methods of JavaScript's Array prototype, so they don't rely on any external libraries.

**Special JS feature or syntax:**

None of the operations tested rely on special JavaScript features or syntax beyond standard JavaScript language constructs.

**Other alternatives:**

If you needed to implement these operations yourself without using the `Array.prototype` methods, you could use a different data structure, such as an array with push and pop operations. However, this approach would likely be less efficient than using the built-in `unshift` and `filter` methods, especially for large arrays.

Additionally, if you were to implement these operations from scratch without relying on the `Array.prototype`, you could use a data structure like a linked list or a heap to achieve similar performance characteristics. However, this would require implementing complex logic and data structures that are not commonly used in everyday JavaScript development.

Keep in mind that the benchmark's focus is on comparing the performance of these two built-in methods, so it's likely that any alternatives would be less relevant or impractical for most use cases.

Related benchmarks:

filter and unshift (version: 0)

Comparing performance of: unshift vs filter

Created: 3 years ago by: Guest

Jump to the latest result

unshift

filter

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):