Benchmark: Filter + pop vs Filter + at

Tests:

filter + pop
const arr = [{name: 'jean',index: 1},{name: 'mark',index: 2},{name: 'jean',index: 3}, {name: 'mark',index: 4}] for(let i = 0; i < 10000; i++){ const item = arr.filter(item => item.name === 'jean').pop() }
filter + at
const arr = [{name: 'jean',index: 1},{name: 'mark',index: 2},{name: 'jean',index: 3}, {name: 'mark',index: 4}] for(let i = 0; i < 10000; i++){ const item = arr.filter(item => item.name === 'jean').at(-1) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
filter + pop
filter + at

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**Benchmark Definition**

The provided JSON represents a benchmark definition, which is a set of instructions for creating and running a JavaScript microbenchmark. In this case, we have two test cases: "Filter + pop" and "Filter + at".

**What is being tested?**

We are testing the performance of two approaches:

1. **Filter + pop**: This approach uses the `filter()` method to create an array with elements that match a certain condition (in this case, `item.name === 'jean'`). The `pop()` method is then used to remove and return the last element from the filtered array.
2. **Filter + at**: Similar to the previous approach, but instead of using `pop()`, we use the `at()` method with an index `-1` to get the last element from the filtered array.

**Options compared**

The two approaches differ in how they access the last element from the filtered array:

* `filter() + pop()`: Creates a new array with elements that match the condition, and then uses `pop()` to remove and return the last element.
* `filter() + at()`: Creates a new array with elements that match the condition, and then uses `at()` with an index `-1` to get the last element.

**Pros and Cons**

Here are some pros and cons of each approach:

* **Filter + pop**:
	+ Pros: Simple and straightforward. The `pop()` method is widely supported by most browsers.
	+ Cons: May create a new array object, which can lead to increased memory allocation and garbage collection overhead.
* **Filter + at()**:
	+ Pros: Can avoid creating a new array object, as the original array is modified in-place. This can reduce memory allocation and garbage collection overhead.
	+ Cons: The `at()` method may not be supported by all browsers, and its behavior can vary depending on the browser implementation.

**Library usage**

There are no libraries explicitly mentioned in the benchmark definition. However, some JavaScript engines and browsers provide additional features or optimizations that might affect performance. For example:

* **Chrome 117**: The benchmark is executed in Chrome 117, which may have additional optimizations or features enabled (e.g., `at()` method support).

**Special JS feature or syntax**

There are no special JS features or syntax mentioned in the benchmark definition.

**Other alternatives**

If you want to explore alternative approaches, here are a few options:

* **Using `slice()`**: Instead of using `pop()` or `at()`, you could use `slice()` to create an array with elements that match the condition. This approach may have similar performance characteristics to `filter()` + `pop()`.
* **Using `findLast()`**: Some modern JavaScript engines and browsers support the `findLast()` method, which can be used to find the last element in an array that matches a certain condition.
* **NativeArray methods**: If you're working with native arrays (e.g., using `Array.from()` or `new Int32Array()`) instead of arrays created by `Array.prototype` methods, you may be able to use specialized methods like `lastIndexOf()` or `at()` to access the last element.

Keep in mind that these alternatives may not always outperform the original approach, and their performance characteristics can vary depending on the browser implementation.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36

Browser/OS: Chrome 117 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
filter + pop	3589.7 Ops/sec
filter + at	3955.9 Ops/sec

Related benchmarks:

Filter + pop vs Filter + at (version: 0)

Comparing performance of: filter + pop vs filter + at

Created: one year ago by: Guest

Jump to the latest result

filter + pop

filter + at

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):