Benchmark: if undefined or emptyArray.forEach

Tests:

emptyArray
const emptyArray = [] emptyArray.forEach(() => console.log('should not see this'))
undefined Array
const nonExistentArray = undefined if (nonExistentArray) { nonExistentArray.forEach(() => console.log('should not see this')) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
emptyArray
undefined Array

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/123.0.0.0 Safari/537.36

Browser/OS: Chrome 123 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
emptyArray	107961680.0 Ops/sec
undefined Array	16681605.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and the pros/cons of different approaches.

**Benchmark Overview**

The benchmark is designed to compare two JavaScript implementations:

1. `emptyArray.forEach`
2. `if (undefined) { emptyArray.forEach }`

These tests aim to determine which implementation is faster for iterating over an empty array or checking if an undefined variable has a value that can be iterated over.

**Options Compared**

The benchmark compares the execution time of two approaches:

1. **`emptyArray.forEach`**: This method is called directly on the `emptyArray` object, passing a callback function as its argument.
2. **`if (undefined) { emptyArray.forEach }`**: This approach uses an if-statement to check if `nonExistentArray` is truthy before calling `forEach` on it.

**Pros and Cons**

* **`emptyArray.forEach`**:
	+ Pros: Simple, direct, and efficient way to iterate over an array.
	+ Cons: If the array is empty, this method will not do anything, which might be considered a waste of resources.
* **`if (undefined) { emptyArray.forEach }`**:
	+ Pros: Provides a clear indication that the `forEach` method should only be called when `nonExistentArray` has a value.
	+ Cons: This approach can lead to unnecessary computations if `nonExistentArray` is falsy, introducing overhead for checking conditions.

**Libraries and Special Features**

The benchmark does not use any specific libraries. However, the `forEach` method is a built-in JavaScript function.

**Special JS Feature**

There are no special features mentioned in this benchmark. The code follows standard JavaScript syntax.

**Alternatives**

Other alternatives to compare could be:

* Using `emptyArray.map`, `emptyArray.reduce`, or other array methods that might have different performance characteristics.
* Comparing with other data structures, such as `Set` or objects, which may have different iteration patterns.
* Incorporating other factors like memory allocation, garbage collection, or caching to provide a more comprehensive understanding of performance.

Keep in mind that these alternative benchmarks would require additional setup and testing to ensure accurate results.

Related benchmarks:

if undefined or emptyArray.forEach (version: 0)

to check which implementation is faster

Comparing performance of: emptyArray vs undefined Array

Created: 2 years ago by: Guest

Jump to the latest result

emptyArray

undefined Array

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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