Benchmark: Lodash uniqBy vs Set with Array of object

HTML Preparation code:

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

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

Script Preparation code:

var myArr = Array.from({
    length: 16000
}, () => ({ value: Math.floor(Math.random() * 1000) }));

var myCopy = null;

 
var myArr = Array.from({    length: 16000}, () => ({ value: Math.floor(Math.random() * 1000) }));​var myCopy = null;

Tests:

Lodash uniqBy
myCopy = _.uniqBy(myArr, 'value').map(({ value }) => value);
myCopy = _.uniqBy(myArr, 'value').map(({ value }) => value);
new Set() Destructuring
myCopy = [...new Set(myArr.map(({ value }) => value))]
myCopy = [...new Set(myArr.map(({ value }) => value))]

uniq for loop

var seen = {};
var out = [];
const len = myArr.length;
var j = 0;
for (var i = 0; i < len; i += 1) {
	var item = myArr[i].value;
  if (seen[item] !== 1) {
  	seen[item] = 1;
    out[j++] = item;
  }
}
myCopy = out;

 
var seen = {};var out = [];const len = myArr.length;var j = 0;for (var i = 0; i < len; i += 1) {    var item = myArr[i].value;  if (seen[item] !== 1) {    seen[item] = 1;    out[j++] = item;  }}myCopy = out;

uniq by forEach

var result = [];
myArr.forEach((item) => {
	if (result.indexOf(item.value) < 0) {
    	result.push(item.value);
    }
});
myCopy = result;

 
var result = [];myArr.forEach((item) => {    if (result.indexOf(item.value) < 0) {        result.push(item.value);    }});myCopy = result;

uniq by filter

var mapMyArr = myArr.map(({ value }) => value);
myCopy = mapMyArr.filter((value, index, array) => array.indexOf(value) === index);

 
var mapMyArr = myArr.map(({ value }) => value);myCopy = mapMyArr.filter((value, index, array) => array.indexOf(value) === index);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Experimental features:

Memory measurements supported only in Chrome.
For precise memory measurements Chrome must be launched with --enable-precise-memory-info flag.
More information: Monitoring JavaScript Memory

Test case name	Result
Lodash uniqBy
new Set() Destructuring
uniq for loop
uniq by forEach
uniq by filter

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36 Edg/133.0.0.0

Browser/OS: Chrome 133 on Windows

View result in a separate tab

Test name	Executions per second
Lodash uniqBy	5564.6 Ops/sec
new Set() Destructuring	3309.5 Ops/sec
uniq for loop	19750.3 Ops/sec
uniq by forEach	1018.5 Ops/sec
uniq by filter	607.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 5 months ago):

Let's dive into the world of JavaScript microbenchmarks.

Benchmark Description

The benchmark tests four different approaches to remove duplicates from an array of objects while preserving the original order:

Lodash uniqBy: Uses Lodash's uniqBy function, which removes duplicate elements from an array based on a unique function.
new Set() with Array destructuring: Uses a Set data structure to remove duplicates and then uses array destructuring to create a new array.
For loop: Iterates through the array using a traditional for loop and checks each element against a set of seen values to avoid duplicates.
forEach() with indexOf(): Iterates through the array using forEach() and checks if an element is already present in the array using indexOf().

Options Compared

The four options are compared in terms of their performance, efficiency, and readability.

Lodash uniqBy: Pros: concise, readable, and easy to use. Cons: may not be as efficient as other approaches.
new Set() with Array destructuring: Pros: efficient, straightforward, and easy to understand. Cons: requires a slight learning curve for those unfamiliar with sets.
For loop: Pros: well-known, familiar algorithm. Cons: verbose, error-prone, and less readable than the other options.
forEach() with indexOf(): Pros: concise, readable. Cons: may not be as efficient as other approaches.

Libraries and Special JS Features

The benchmark uses Lodash's uniqBy function, which is a utility library that provides a simple way to remove duplicates from an array based on a unique function.

There are no special JavaScript features or syntax used in this benchmark.

Benchmark Preparation Code

The preparation code generates an array of 16,000 objects with random values and copies the array to ensure correct results. The myCopy variable is initialized to null, which will be populated with the result of each benchmarking approach.

HTML Preparation Code

The HTML code includes a link to Lodash's CDN, which loads the necessary library for the uniqBy function.

Other Alternatives

There are other approaches to removing duplicates from an array in JavaScript, such as:

Using Array.prototype.filter() and checking if each element is already present in the array.
Using Array.prototype.every() and checking if each element meets a certain condition.
Using a recursive approach with a helper function.

These alternatives may have their own trade-offs in terms of performance, efficiency, and readability.

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**Benchmark Description**

The benchmark tests four different approaches to remove duplicates from an array of objects while preserving the original order:

1. **Lodash `uniqBy`**: Uses Lodash's `uniqBy` function, which removes duplicate elements from an array based on a unique function.
2. **`new Set()` with Array destructuring**: Uses a `Set` data structure to remove duplicates and then uses array destructuring to create a new array.
3. **For loop**: Iterates through the array using a traditional for loop and checks each element against a set of seen values to avoid duplicates.
4. **`forEach()` with `indexOf()`**: Iterates through the array using `forEach()` and checks if an element is already present in the array using `indexOf()`.

**Options Compared**

The four options are compared in terms of their performance, efficiency, and readability.

* **Lodash `uniqBy`**: Pros: concise, readable, and easy to use. Cons: may not be as efficient as other approaches.
* **`new Set()` with Array destructuring**: Pros: efficient, straightforward, and easy to understand. Cons: requires a slight learning curve for those unfamiliar with sets.
* **For loop**: Pros: well-known, familiar algorithm. Cons: verbose, error-prone, and less readable than the other options.
* **`forEach()` with `indexOf()`**: Pros: concise, readable. Cons: may not be as efficient as other approaches.

**Libraries and Special JS Features**

The benchmark uses Lodash's `uniqBy` function, which is a utility library that provides a simple way to remove duplicates from an array based on a unique function.

There are no special JavaScript features or syntax used in this benchmark.

**Benchmark Preparation Code**

The preparation code generates an array of 16,000 objects with random values and copies the array to ensure correct results. The `myCopy` variable is initialized to null, which will be populated with the result of each benchmarking approach.

**HTML Preparation Code**

The HTML code includes a link to Lodash's CDN, which loads the necessary library for the `uniqBy` function.

**Other Alternatives**

There are other approaches to removing duplicates from an array in JavaScript, such as:

* Using `Array.prototype.filter()` and checking if each element is already present in the array.
* Using `Array.prototype.every()` and checking if each element meets a certain condition.
* Using a recursive approach with a helper function.

These alternatives may have their own trade-offs in terms of performance, efficiency, and readability.

Related benchmarks:

Lodash uniqBy vs Set with Array of object (version: 4)

Lodash uniqBy vs [...new Set()]

Comparing performance of: Lodash uniqBy vs new Set() Destructuring vs uniq for loop vs uniq by forEach vs uniq by filter

Created: 4 years ago by: Registered User

Jump to the latest result

Lodash uniqBy

new Set() Destructuring