Benchmark: lodash isUndefined vs typeof === undefined (take 2)

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var foo;

Tests:

lodash.isUndefined
if (_.isUndefined(foo)) { foo; }
Native js
if (foo === undefined) { foo; }
simplify native js
if (!foo) { foo; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash.isUndefined
Native js
simplify native js

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 20 days ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:132.0) Gecko/20100101 Firefox/132.0

Browser/OS: Firefox 132 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
lodash.isUndefined	1024398848.0 Ops/sec
Native js	1030928384.0 Ops/sec
simplify native js	1036307200.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark.

**Benchmark Overview**

The benchmark is comparing three different approaches to check if a variable `foo` is undefined/unexistent:

1. Using Lodash's `isUndefined()` function
2. Using the native JavaScript operator `=== undefined`
3. Simplifying the native JavaScript approach using the `!` operator

**Options Compared**

We have three options being compared:

* **Lodash.isUndefined()**: This uses the `lodash.isUndefined()` function, which is a utility function from the Lodash library. It returns `true` if the given value is undefined.
* **Native js === undefined**: This uses the native JavaScript operator `=== undefined` to check if the variable `foo` is undefined. The `===` operator checks for exact equality between two values, and in this case, it's being used to compare with the `undefined` keyword.
* **Simplify native js !foo**: This simplifies the native JavaScript approach by using the `!` operator to negate the value of `foo`. If `foo` is falsey (i.e., it's `null`, `undefined`, 0, an empty string, etc.), this expression will evaluate to true. Otherwise, it will evaluate to false.

**Pros and Cons**

* **Lodash.isUndefined()**: This approach provides a more explicit and readable way of checking if a value is undefined. However, it comes with a performance cost since it involves calling a function from the Lodash library.
	+ Pros: More explicit and readable
	+ Cons: Performance overhead due to library call
* **Native js === undefined**: This approach is simple and lightweight, but it's also more prone to errors if not used correctly. The `===` operator can be confused with other comparisons, making it harder to read.
	+ Pros: Lightweight and simple
	+ Cons: Prone to errors and less readable
* **Simplify native js !foo**: This approach is a good compromise between the two. It's lightweight and easy to understand, but still provides some readability benefits by using a clear operator (`!`).
	+ Pros: Balanced performance and readability
	+ Cons: May require additional mental processing to understand the operator's meaning

**Library and Special JS Feature**

The benchmark uses Lodash, which is a popular utility library for JavaScript. It provides various functions for tasks like string manipulation, array operations, and more.

There are no special JavaScript features or syntax being tested in this benchmark.

**Alternatives**

Other alternatives to check if a variable is undefined/unexistent include:

* Using `typeof` with the `undefined` keyword: `typeof foo === 'undefined'`
* Using the `||` operator with an empty string: `foo || ''
* Using the `in` operator with `undefined`: `foo in undefined`

However, these alternatives are not tested in this benchmark.

**Conclusion**

In conclusion, this benchmark is testing three different approaches to check if a variable is undefined/unexistent: using Lodash's `isUndefined()` function, native JavaScript's `=== undefined` operator, and simplifying the native approach with the `!` operator. The pros and cons of each approach are discussed, highlighting the trade-offs between readability, performance, and simplicity.

Related benchmarks:

lodash isUndefined vs typeof === undefined (take 2) (version: 0)

Comparing performance of: lodash.isUndefined vs Native js vs simplify native js

Created: 3 years ago by: Guest

Jump to the latest result

lodash.isUndefined

Native js

simplify native js

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):