Benchmark: lodash keyBy and groupBy

HTML Preparation code:

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

Script Preparation code:

var max2 = 1000000; // 1,000,000 (10 Million)

var data = [];
for (var i = 0; i <= max2; i++) { data.push({ id: i }); }

Tests:

keyBy
_.keyBy(data, ({ id }) => id)
groupBy
_.groupBy(data, ({ id }) => id)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
keyBy
groupBy

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.

I'd be happy to explain the benchmark and its options.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark test case for the `lodash` library, specifically testing the `keyBy` and `groupBy` functions. The goal of this benchmark is to compare the performance of these two functions on a large dataset of 1 million objects.

**Options Compared**

The two options being compared are:

1. `_.keyBy(data, ({ id }) => id)`
2. `_.groupBy(data, ({ id }) => id)`

These two functions achieve similar goals: creating an object where the keys are the unique values from the original array and the corresponding values are arrays of elements that have those keys.

**Pros and Cons**

Here's a brief summary of each option:

1. **_.keyBy(data, ({ id }) => id)**
	* Pros:
		+ More efficient in terms of memory usage (no unnecessary array creation)
		+ Can be faster due to optimized internal implementation
	* Cons:
		+ May not be as readable or intuitive for some developers
2. **_.groupBy(data, ({ id }) => id)**
	* Pros:
		+ More readable and intuitive for some developers
		+ Uses a more traditional array-based approach that might be easier to understand
	* Cons:
		+ Less efficient in terms of memory usage (creates an intermediate array)
		+ Might be slower due to the overhead of array creation and manipulation

**Library and Its Purpose**

The `lodash` library is a popular JavaScript utility library that provides a wide range of functions for tasks such as string manipulation, array manipulation, object manipulation, and more. In this benchmark, `lodash` is used to provide optimized implementations of the `keyBy` and `groupBy` functions.

**Special JS Feature or Syntax**

There are no specific JavaScript features or syntaxes mentioned in the benchmark code. However, it's worth noting that the use of an arrow function (`({ id }) => id`) is a modern JavaScript feature that allows for concise and expressive function definitions.

**Other Alternatives**

If you're not using `lodash`, there are other libraries and approaches you could consider:

1. **Built-in Array Methods**: You can achieve similar results using built-in array methods like `map()`, `reduce()`, and `forEach()` in combination with object literals.
2. **Underscore.js (Alternative)**: If you want to use a different library, you could try `underscore.js`, which provides similar functions for working with objects and arrays.
3. **Custom Implementation**: You can also write your own implementation of the `keyBy` and `groupBy` functions using vanilla JavaScript.

Keep in mind that these alternatives might not be as optimized or efficient as the `lodash` implementations, but they could provide a good starting point if you don't need the full feature set of `lodash`.

Related benchmarks:

lodash keyBy and groupBy (version: 0)

Comparing performance of: keyBy vs groupBy

Created: 2 years ago by: Guest

Jump to the latest result

keyBy

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):