Benchmark: lodash.head() vs [0] updated with optional chaining

lodash.head() vs [0] updated with optional chaining (version: 0)

Is head() needed only to check length !== 0 ? P.s. Empty testcase for [0] is useless because it won't crash on trying to get nonexistent element

Comparing performance of: Not empty lodash.head() vs Not empty [0] vs Empty lodash.head() vs Empty [0] vs [0] with check vs [0] with null check vs [0] with optional chaining null check

Created: 4 years ago by: Guest

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HTML Preparation code:

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

Script Preparation code:

var a = [1,2,3];
var e = [];

Tests:

Not empty lodash.head()
_.head(a)
Not empty [0]
a[0]
Empty lodash.head()
_.head(e)
Empty [0]
e[0]
[0] with check
e.length ? e[0] : undefined
[0] with null check
e && e.length ? e[0] : undefined
[0] with optional chaining null check
e?.[0]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Not empty lodash.head()
Not empty [0]
Empty lodash.head()
Empty [0]
[0] with check
[0] with null check
[0] with optional chaining null check

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Windows

View result in a separate tab

Test name	Executions per second
Not empty lodash.head()	115241128.0 Ops/sec
Not empty [0]	216992864.0 Ops/sec
Empty lodash.head()	118182208.0 Ops/sec
Empty [0]	215156256.0 Ops/sec
[0] with check	192984160.0 Ops/sec
[0] with null check	173685696.0 Ops/sec
[0] with optional chaining null check	226043392.0 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 its test cases.

**Benchmark Overview**

The test compares the performance of different approaches to access the first element (`[0]`) of an array in JavaScript:

1. Direct indexing (`a[0]`)
2. Using `_.head()` from Lodash
3. Optional chaining (`e?.[0]`)

These tests aim to evaluate which approach is most efficient, especially when dealing with empty arrays.

**Direct Indexing (a[0])**

This method directly accesses the first element of an array using square brackets (`[]`). If the array is empty, this will result in a `NaN` (Not a Number) value and may cause issues if not properly checked for emptiness.

Pros: Simple, straightforward approach.
Cons: May lead to unexpected behavior when dealing with empty arrays, as it can return `NaN`.

**Lodash _.head()`**

The `_.head()` function returns the first element of an array. If the array is empty, it will return `undefined`. This method checks for emptiness before attempting to access the first element.

Pros: Explicitly handles empty arrays by returning `undefined`, reducing the risk of unexpected behavior.
Cons: Requires importing Lodash and may incur additional overhead due to function call and lookup costs.

**Optional Chaining (`e?.[0]`)**

Optional chaining is a syntax introduced in ECMAScript 2020 (ES10) that allows accessing nested properties or calling methods on objects without throwing errors if the property or method does not exist. In this case, `e?.[0]` attempts to access the first element of an array (`e`) using optional chaining.

Pros: Simplifies handling empty arrays by returning `undefined`, reducing the risk of unexpected behavior.
Cons: May incur additional overhead due to function call and lookup costs, although these are generally smaller compared to the overhead of Lodash's `_head()` method.

**Other Considerations**

*   If the array is very large, the performance difference between these approaches may be negligible.
*   Using `_.head()` or optional chaining can help reduce bugs related to accessing empty arrays. However, this comes at a cost in terms of performance and potential additional library imports.
*   The tests use Chrome 99 as the browser and Mac OS X 10.15.7 as the operating system. This might impact the results due to differences in JavaScript engine versions or platform-specific optimizations.

**Alternatives**

Other approaches to access the first element of an array include:

1. Using `Array.prototype[0]`: Similar to direct indexing but with additional overhead for prototype lookup.
2. Using `for...of` loop: Iterates over the array elements using a `for...of` loop, which might be slower than direct indexing or optional chaining.

Keep in mind that these alternatives may incur additional overhead and are generally less efficient compared to the tested approaches.

In summary, this benchmark compares the performance of different methods for accessing the first element of an array: Direct indexing (`a[0]`), Lodash's `_.head()`, and optional chaining (`e?.[0]`). The results will help users choose the most suitable approach based on their specific use case requirements.

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