Benchmark: Lodash.countBy vs native filter

HTML Preparation code:

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

Script Preparation code:

var values = [
  {
  	f: true,
  },
  {
  	f: true,
  },
  {
  	f: true,
  },
  {
  	f: true,
  },
  {
  	f: false,
  },
  {
  	f: true,
  },
  {
  	f: false,
  },
  {
  	f: false,
  },
  {
  	f: false,
  },
  {
  	f: false,
  },
]

Tests:

native filter
values.filter(_item => _item.f).length
lodash countBy
_.countBy(values, 'f').true

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
native filter
lodash countBy

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation.

The provided JSON represents a benchmark test case on MeasureThat.net, which compares the performance of two approaches: native JavaScript filtering and using Lodash's `countBy` function.

**Native Filtering**

The first test case uses native JavaScript filtering to count the occurrences of a specific property (`f`) in an array of objects. The benchmark definition is:
```javascript
values.filter(_item => _item.f).length
```
This code creates an array `values` and filters it using the `filter()` method, which returns an array with only the elements that pass the test (in this case, the ones with a truthy value for the `f` property). The resulting array is then passed to the `length` property, which returns the number of elements in the array.

**Lodash's `countBy` Function**

The second test case uses Lodash's `countBy` function to count the occurrences of a specific property (`f`) in an array of objects. The benchmark definition is:
```javascript
_.countBy(values, 'f').true
```
This code creates an array `values` and passes it to the `countBy` function along with the key (`'f'`) as an argument. The `countBy` function returns an object with the counts for each unique value in the array. In this case, we only care about the truthy values, so we call the `.true()` method on the resulting object to get the count.

**Options Compared**

The two approaches are compared in terms of execution time and number of executions per second (ExecutionsPerSecond). The test measures which approach is faster and more efficient.

**Pros and Cons**

* **Native Filtering:**
	+ Pros:
		- No external dependency on Lodash
		- Can be implemented using a simple and well-known JavaScript method (filter())
	+ Cons:
		- May require more manual handling of edge cases (e.g., null or undefined values)
* **Lodash's `countBy` Function:**
	+ Pros:
		- Simplifies the counting logic
		- Provides a convenient way to handle multiple keys and edge cases
	+ Cons:
		- Introduces an external dependency on Lodash, which may add overhead

**Library: Lodash**

Lodash is a popular JavaScript utility library that provides a collection of high-order functions for functional programming. In this case, `countBy` is used to count the occurrences of a specific property in an array of objects.

**Special JS Feature/ Syntax**

There are no special features or syntax mentioned in the benchmark definition. However, it's worth noting that Lodash's `countBy` function uses a technique called "memoization" to optimize performance, which can be beneficial for this type of counting operation.

**Alternatives**

If you want to implement native filtering without using Lodash, you can use other JavaScript methods such as:

* Using the `reduce()` method instead of `filter()`
* Implementing your own counting logic using loops and conditional statements

Keep in mind that these alternatives may require more manual handling of edge cases and may not be as efficient as Lodash's `countBy` function.

Related benchmarks:

Lodash.countBy vs native filter (version: 0)

Lodash.countBy vs native filter

Comparing performance of: native filter vs lodash countBy

Created: 3 years ago by: Registered User

Jump to the latest result

native filter

lodash countBy

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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