Benchmark: native find vs for..in

HTML Preparation code:

<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.core.js"></script>

Script Preparation code:

var users = [
  { 'user': 'joey',  'age': 32 },
  { 'user': 'ross',    'age': 41 },
  { 'user': 'chandler', 'age': 39 }
]

Tests:

array find
// Native users.find(function (o) { return o.age < 40; })
_.find
for (let key in users) { if (users.hasOwnProperty(key)) { let value = users[key]; if (users[key].age < 40) return users[key]; } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array find
_.find

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
array find	148646400.0 Ops/sec
_.find	16062472.0 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 benchmarking test case and explain what's being tested, compared, and their pros and cons.

**What is tested?**

The provided benchmark measures the performance difference between two approaches:

1. **Native `find` method**: This uses JavaScript's built-in `Array.prototype.find()` method to find the first element in an array that satisfies a certain condition.
2. **Traditional `for...in` loop with `hasOwnProperty` check**: This is a manual approach using a `for...in` loop and checking if each property exists on the object (using `hasOwnProperty`) before accessing it.

**Options compared**

The benchmark compares these two approaches to measure their performance differences.

**Pros and Cons of each approach:**

1. **Native `find` method**:
	* Pros:
		+ Efficient, as it stops searching as soon as it finds a match.
		+ Implemented in native code, making it faster than interpreted JavaScript code.
	* Cons:
		+ Requires the array to have at least one element for `find()` to work (if not, it will return `undefined`).
2. **Traditional `for...in` loop with `hasOwnProperty` check**:
	* Pros:
		+ Can handle arrays of any length.
		+ Simple and easy to understand.
	* Cons:
		+ Slower than native `find()` due to the overhead of the loop and checks.

**Library used:**

The benchmark includes a reference to Lodash's `_` library, specifically `lodash.core.js`. This library is not directly involved in the performance comparison but provides additional functionality that might be useful for more complex tasks. In this case, it's likely included as part of the HTML preparation code to enable the use of Lodash's features in the benchmark.

**Special JavaScript feature:**

There are no special JavaScript features or syntaxes used in these tests, other than those inherent to the `find()` method and the `for...in` loop.

**Other alternatives:**

If you want to compare performance with alternative methods, consider the following approaches:

1. **Using `Array.prototype.findIndex()`**: Similar to `Array.prototype.find()`, but returns `-1` if no element matches the condition.
2. **Using a `while` loop**: An alternative to the traditional `for...in` loop approach.
3. **Using `slice()` and indexing**: Another way to access elements in an array, potentially with performance differences compared to native `find()` or manual loops.

Keep in mind that performance differences between these approaches can be significant, especially for large arrays. It's essential to consider the specific requirements of your use case when choosing a method.

Related benchmarks:

native find vs for..in (version: 0)

Compare the new ES6 spread operator with the traditional concat() method

Comparing performance of: array find vs _.find

Created: 2 years ago by: Guest

Jump to the latest result

array find

_.find

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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