Benchmark: var is a non-empty array (v2)

var is a non-empty array (v2) (version: 0)

Micro-benchmark various method of checking for non-empty array on arbitrary variable

Comparing performance of: IsArray (array) vs IsArray (null) vs typecheck (nullable dot) (array) vs typecheck (nullable dot) (null) vs manual check cond (array) vs manual check cond (null) vs typeof obj + length (array) vs typeof obj + length (null)

Created: one year ago by: Guest

Jump to the latest result

Script Preparation code:

var arr = [1,2,3];
var notArr = null;

Tests:

IsArray (array)
Array.isArray(arr) && arr.length > 0
IsArray (null)
Array.isArray(notArr) && notArr.length > 0
typecheck (nullable dot) (array)
arr?.length > 0 && arr[0] !== undefined
typecheck (nullable dot) (null)
notArr?.length > 0 && notArr[0] !== undefined
manual check cond (array)
arr !== null && arr !== undefined && arr.length > 0 && arr[0] !== undefined
manual check cond (null)
notArr !== null && notArr !== undefined && notArr.length > 0 && notArr[0] !== undefined
typeof obj + length (array)
typeof arr === 'object' && arr !== null && arr.length > 0 && arr[0] !== undefined
typeof obj + length (null)
typeof notArr === 'object' && notArr !== null && notArr.length > 0 && notArr[0] !== undefined

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
IsArray (array)
IsArray (null)
typecheck (nullable dot) (array)
typecheck (nullable dot) (null)
manual check cond (array)
manual check cond (null)
typeof obj + length (array)
typeof obj + length (null)

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days 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 for testing various methods to check if a variable is a non-empty array. The script preparation code creates two variables: `arr` (an array with elements) and `notArr` (null). The HTML preparation code is empty, indicating that no HTML content is involved in this benchmark.

**Test Cases**

There are six test cases, each comparing different approaches to check if a variable is an array. Let's break them down:

1. **IsArray (array)**: Checks if `arr` is an array using `Array.isArray(arr)` and verifies its length is greater than 0.
2. **IsArray (null)**: Similar to the previous test, but checks if `notArr` is an array (which it's not).
3. **typecheck (nullable dot) (array)**: Uses optional chaining (`?.`) to access the length property of `arr`, ensuring it exists and is not null or undefined.
4. **typecheck (nullable dot) (null)**: Similar to the previous test, but checks if `notArr` has a valid length property using optional chaining.
5. **manual check cond (array)**: Verifies that `arr` meets multiple conditions: not being null or undefined, having a positive length, and its first element not being undefined.
6. **manual check cond (null)**: Similar to the previous test, but checks if `notArr` meets similar conditions.

**Library**

The `Array.isArray()` function is a built-in JavaScript method that checks if an object is an array. It's not a library in the classical sense, but rather a native JavaScript API.

**Optional Chaining (`?.`)**

Optional chaining is a new feature introduced in ECMAScript 2020 (ES10). It allows you to access nested properties of an object without throwing an error if the property doesn't exist. The syntax `obj.prop1?.prop2` returns `undefined` if `prop1` or `prop2` doesn't exist.

**Pros and Cons**

Here are some pros and cons for each approach:

* **IsArray (array)**: Pros - simple, straightforward; Cons - may not work for arrays with large numbers of elements.
* **typecheck (nullable dot) (array)**: Pros - efficient, avoids unnecessary checks; Cons - requires optional chaining support, which is relatively new.
* **manual check cond (array)**: Pros - guarantees correctness but may be slower; Cons - more complex and error-prone.
* **typecheck (nullable dot) (null)**: Pros - similar to the previous test, with slightly different behavior for null. Cons - less efficient than `Array.isArray()`.

**Other Considerations**

When working with arrays in JavaScript, it's essential to consider the following:

* When checking if an array exists, use `Array.isArray()` or optional chaining (`?.`) instead of relying on the `typeof` operator.
* Be mindful of array performance and optimize checks when possible.
* Use manual check conditions judiciously, as they can lead to more complex code.

**Alternatives**

If you're looking for alternative approaches, consider the following:

* Use a library like `lodash` or `ramda`, which provide various utility functions for working with arrays.
* Implement your own array utilities using JavaScript's built-in methods and syntax features (e.g., `map()`, `filter()`, `reduce()`).
* Explore modern JavaScript frameworks and libraries, such as React or Angular, which offer optimized array handling and utilities.

Take a deep breath, and now you're ready to tackle more complex JavaScript challenges!

Latest run results:

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

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/114.0

Browser/OS: Firefox 114 on Ubuntu

View result in a separate tab

Test name	Executions per second
IsArray (array)	102162696.0 Ops/sec
IsArray (null)	119560152.0 Ops/sec
typecheck (nullable dot) (array)	320817952.0 Ops/sec
typecheck (nullable dot) (null)	470962688.0 Ops/sec
manual check cond (array)	420352160.0 Ops/sec
manual check cond (null)	698253568.0 Ops/sec
typeof obj + length (array)	431785728.0 Ops/sec
typeof obj + length (null)	717073856.0 Ops/sec

Related benchmarks:

var is a non-empty array (v2) (version: 0)

Micro-benchmark various method of checking for non-empty array on arbitrary variable

Comparing performance of: IsArray (array) vs IsArray (null) vs typecheck (nullable dot) (array) vs typecheck (nullable dot) (null) vs manual check cond (array) vs manual check cond (null) vs typeof obj + length (array) vs typeof obj + length (null)

Created: one year ago by: Guest

Jump to the latest result

IsArray (array)

IsArray (null)

typecheck (nullable dot) (array)

typecheck (nullable dot) (null)

manual check cond (array)

manual check cond (null)

typeof obj + length (array)

typeof obj + length (null)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):