Benchmark: filter vs. groupBy (fixed again)

Script Preparation code:

var 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;
  }, {});
};

Tests:

filter
posts.filter(p => p.type === 'foo').length; posts.filter(p => p.type === 'bar').length; posts.filter(p => p.type === 'baz').length; posts.filter(p => p.type === 'foo').length;
groupBy
var 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):

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark compares the performance of two approaches: `filter` and `groupBy`. Both methods are used to process an array of objects, where each object has a specific property (`type`) that determines its grouping.

**`filter` Method**

The `filter` method is a built-in JavaScript function that takes a predicate function as an argument. It returns a new array containing only the elements for which the predicate returns `true`.

In this benchmark, the `filter` method is used to count the number of elements in each group (e.g., `posts.filter(p => p.type === 'foo').length;`). The results are compared to determine which approach is faster.

**Pros and Cons:**

Pros:

* Easy to implement
* Built-in function, so it's available on all JavaScript engines

Cons:

* Can lead to unnecessary array creations if the predicate function returns `true` for multiple elements in a row
* May not be optimized for performance by the JavaScript engine

**`groupBy` Method**

The `groupBy` method is a custom implementation that groups an array of objects based on a specific key. In this benchmark, it's used to count the number of elements in each group (e.g., `postsByType.foo.length;`). The results are compared to determine which approach is faster.

**Pros and Cons:**

Pros:

* Can be more efficient than the `filter` method if implemented correctly
* Allows for better control over the grouping process

Cons:

* Requires custom implementation, which can add complexity
* May require additional memory allocation for the grouped arrays

**Library Used (if any)**

None.

**Special JS Feature or Syntax**

None mentioned in this benchmark.

**Benchmark Preparation Code Explanation**

The `Script Preparation Code` section defines an array of objects (`posts`) with a specific property (`type`). The `Html Preparation Code` section is empty, indicating that no HTML code is necessary for this benchmark.

**Other Alternatives**

If the `filter` method were not available, the benchmark could have used other approaches, such as:

* Using a custom loop to iterate over the array and count elements
* Using a library like Lodash or Ramda for grouping and filtering
* Using a different programming language that supports built-in array processing functions

However, it's worth noting that these alternatives would likely introduce additional complexity and may not provide a fair comparison with the `filter` method.

Related benchmarks:

filter vs. groupBy (fixed again) (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):