Benchmark: filter null vs negation

Script Preparation code:

var ops = [true, 1, false, 3, 4, 5, true, "foobar", {}, 3, 4, 5, 6, [], false, 2, true, 2, false, 212, true, 34, 1, 1.909090090909009090909090909, undefined];

Tests:

null check
ops.filter(op => op === null)
negation check
ops.filter(op => !op)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
null check
negation check

Fastest: N/A

Slowest: N/A

Autogenerated LLM Sumamry (model llama3.2:3b, generated 10 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**Benchmark Overview**

The benchmark is designed to measure the performance difference between two approaches for filtering an array in JavaScript: using `null` checks and using negation (`!`) operators.

**Options Compared**

There are two options being compared:

1. **Null Check**: This approach uses the `=== null` operator to check if an element is `null`. It's likely that this option will use a loop or recursion to iterate through the array and perform the null check.
2. **Negation**: This approach uses the `!` operator to negate the value of each element, effectively checking for falsiness instead of nullity. It may also use loops or other methods to iterate through the array.

**Pros and Cons**

* **Null Check**
	+ Pros: More explicit and straightforward way to check for null values.
	+ Cons: May be slower due to the additional comparison operation.
* **Negation**
	+ Pros: Can be faster since it eliminates the need for an explicit null check, but may have performance implications if not optimized correctly.
	+ Cons: May lead to unexpected results if not understood properly (e.g., `null` values will be considered falsy).

**Library and Purpose**

In this benchmark, no specific JavaScript library is being used. The code snippet provided only contains a simple array of operations (`ops`) that needs to be filtered.

**Special JS Feature or Syntax**

There's no special feature or syntax mentioned in the benchmark definition or test cases. However, it's worth noting that `null` checks and negation are basic JavaScript concepts that are widely supported across most browsers and environments.

**Other Alternatives**

If you'd like to explore alternative approaches for filtering arrays, here are a few options:

1. Using `Array.prototype.filter()` with an arrow function: `ops.filter(op => op === null)`. This approach is concise and efficient but may have performance implications depending on the browser or environment.
2. Using `Array.prototype.every()` with a callback function: `ops.every((op, index) => op === null)`. This approach is less common for filtering arrays but can be more readable in certain cases.
3. Using a custom implementation with bitwise operations (e.g., using `& 0` to check for zero): `ops.filter(op => op & 0 === 0)`. This approach might provide performance benefits, but its readability and maintainability may suffer.

In summary, the benchmark compares two approaches for filtering an array in JavaScript: using `null` checks and using negation (`!`) operators. The choice between these options depends on your specific use case and priorities (e.g., readability vs. performance).

Latest run results:

Run details: (Test run date: 4 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36

Browser/OS: Chrome 125 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
null check	22565380.0 Ops/sec
negation check	14641790.0 Ops/sec

Related benchmarks:

filter null vs negation (version: 0)

Comparing performance of: null check vs negation check

Created: 4 months ago by: Guest

Jump to the latest result

null check

negation check

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Sumamry (model llama3.2:3b, generated 10 days ago):