Benchmark: lodash uniq vs Map

HTML Preparation code:


<script src='https://cdn.jsdelivr.net/npm/lodash@4.17.10/lodash.min.js'></script>

Tests:

Map
const arr = [{id: 1}, {id: 2}, {id: 3}, {id: 1}, {id: 2}, {id: 3}, {id: 1}, {id: 2}, {id: 3}]; const uniqs = []; const map = new Map(); for (const item of arr) { if (!map.has(item.id)) { map.set(item.id, item.id); uniqs.push(item); } } return uniqs;
use lodash
var l = [{id: 1}, {id: 2}, {id: 3}, {id: 1}, {id: 2}, {id: 3}, {id: 1}, {id: 2}, {id: 3}]; return _.uniq(l);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map
use lodash

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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Let's break down the benchmark and analyze what's being tested.

**Benchmark Overview**

The benchmark measures the performance of two approaches: using a `Map` data structure in JavaScript to remove duplicates, and using the `uniq()` function from the Lodash library to achieve the same result.

**Test Cases**

There are two test cases:

1. **"Map"`**: This test case creates an array of objects with duplicate `id` properties and then uses a `Map` to remove duplicates while preserving the original order. The resulting array is returned.
2. **"use lodash"`**: This test case uses the `uniq()` function from Lodash to remove duplicates from the same array as in the previous test case.

**Approaches Compared**

The two approaches differ in how they handle duplicate values:

1. **"Map"`**: The `Map` data structure is used to store unique keys (in this case, the `id` properties). When a new value is added, it's checked if the key already exists in the map. If not, the key-value pair is stored and the value is added to the resulting array.
2. **"use lodash"`**: The `uniq()` function uses a different algorithm to remove duplicates, which involves iterating through the input array, comparing values using a custom comparison function, and storing unique values in an internal data structure.

**Pros and Cons**

Here are some pros and cons of each approach:

1. **"Map"`**:
	* Pros:
		+ Preserves the original order of elements.
		+ Can be more efficient for large datasets since it uses a hash-based data structure.
	* Cons:
		+ Requires more code to implement.
		+ May have higher memory usage due to the internal map data structure.
2. **"use lodash"`**:
	* Pros:
		+ Simplifies code and reduces implementation overhead.
		+ Often implemented in a way that's optimized for performance.
	* Cons:
		+ Preserves only the first occurrence of each value (not necessarily preserving order).
		+ May have higher memory usage due to the internal data structure.

**Lodash Library**

The `uniq()` function from Lodash is a utility function that removes duplicate values from an array while preserving the original order. It uses a custom comparison function to compare elements, which ensures that objects with different properties are considered duplicates.

**Other Considerations**

When choosing between these approaches, consider the following:

* Performance: If you need to process large datasets, using `Map` might be more efficient since it uses a hash-based data structure.
* Code simplicity: Using Lodash's `uniq()` function can simplify your code and reduce implementation overhead.
* Data preservation: If preserving the original order of elements is crucial, using `Map` is likely a better choice.

**Alternatives**

Other alternatives for removing duplicates from an array include:

1. **Using `Set`**: Similar to `Map`, but without preserving the original order.
2. **Sorting and filtering**: Sorting the array by a unique property and then filtering out duplicate elements can be an alternative approach.
3. **Using a library like Underscore.js or Ramda**: These libraries provide various functions for working with arrays, including removing duplicates.

I hope this explanation helps you understand what's being tested in this benchmark!

Related benchmarks:

lodash uniq vs Map (version: 0)

Comparing performance of: Map vs use lodash

Created: 5 years ago by: Guest

Jump to the latest result

Map

use lodash

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):