Benchmark: filter vs. groupBy (fixed)

Tests:

filter
const posts = [ { id: 1, type: 'foo' }, { id: 2, type: 'bar' }, { id: 3, type: 'baz' }, { id: 4, type: 'foo' }, { id: 5, type: 'bar' }, { id: 6, type: 'baz' }, { id: 7, type: 'foo' }, { id: 8, type: 'bar' }, { id: 9, type: 'baz' } ]; posts.filter(p => p.type === 'foo').length; posts.filter(p => p.type === 'foo').length; posts.filter(p => p.type === 'foo').length; posts.filter(p => p.type === 'foo').length;
groupBy
const posts = [ { id: 1, type: 'foo' }, { id: 2, type: 'bar' }, { id: 3, type: 'baz' }, { id: 4, type: 'foo' }, { id: 5, type: 'bar' }, { id: 6, type: 'baz' }, { id: 7, type: 'foo' }, { id: 8, type: 'bar' }, { id: 9, type: 'baz' } ]; var groupBy = function(xs, key) { return xs.reduce(function(rv, x) { (rv[x[key]] = rv[x[key]] || []).push(x); return rv; }, {}); }; const postsByType = groupBy(posts, 'type') postsByType.foo.length; postsByType.bar.length; postsByType.baz.length; postsByType.foo.length;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
filter
groupBy

Fastest: N/A

Slowest: N/A

Latest run results:

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

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**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark measures the performance of two different approaches: filtering an array using the `filter()` method versus grouping an array using the `groupBy()` function.

**Filtering Approach (Test Case: "filter")**

The filtering approach uses the `filter()` method to remove elements from an array that do not match a specified condition. In this case, the condition is `p.type === 'foo'`. The `filter()` method iterates over each element in the array and returns a new array containing only the elements that pass the test.

**Grouping Approach (Test Case: "groupBy")**

The grouping approach uses a custom function called `groupBy()` to group an array of objects by a specified key. In this case, the key is `'type'`. The `groupBy()` function iterates over each element in the array and adds it to an object in the result array, using the value of the key as the property name.

**Options Compared**

The two approaches are compared in terms of performance:

1. **Filtering Approach**
	* Pros:
		+ Easy to implement
		+ Fast iteration over the array
	* Cons:
		+ May require multiple iterations if the condition is complex or involves expensive computations
		+ Creates a new array, which can consume memory
2. **Grouping Approach**
	* Pros:
		+ Can be more efficient than filtering for large datasets
		+ Reduces the number of iterations required
	* Cons:
		+ More complex implementation
		+ May require additional memory to store the result objects

**Library and Special JS Features**

The `groupBy()` function uses a library called Lodash, which provides a utility function for grouping arrays by key. Lodash is a popular JavaScript library that provides a set of reusable functions for tasks such as array manipulation, object creation, and more.

**Other Considerations**

* **Memory Consumption**: The filtering approach may consume more memory than the grouping approach if the input array is large.
* **Complexity**: The grouping approach requires more complex logic than the filtering approach, which can make it harder to understand and maintain.
* **Browser Support**: Both approaches should work in modern browsers, but older browsers may not support the `groupBy()` function.

**Alternatives**

If you need to group arrays by key, Lodash is a popular library that provides a simple and efficient implementation. However, if you want to implement grouping manually without using an external library, you can use a similar approach as shown in the benchmark code.

If you prefer not to use the `groupBy()` function or Lodash, you can consider alternative approaches such as:

1. **Object Oriented Programming (OOP)**: You can create a class that implements the grouping behavior and uses iteration over the array.
2. **Manual Iteration**: You can use manual iteration over the array to achieve the same result as the `groupBy()` function.

In summary, the filtering approach is easy to implement and suitable for most cases, while the grouping approach provides better performance for large datasets but requires more complex logic and memory.

Related benchmarks:

filter vs. groupBy (fixed) (version: 0)

Comparing performance of: filter vs groupBy

Created: 3 years ago by: Guest

Jump to the latest result

filter

groupBy

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):